Showing posts with label evolution. Show all posts
Showing posts with label evolution. Show all posts

Thursday, 25 April 2024

Why humans don't have tails. Genetic basis for our tail-loss evolution.

Unlike our domestic cat companions we don't have tails. You've probably noticed! πŸ˜‰πŸ˜Ž But we might have had tails and think how different the world would be if we had retained our tails like our primate cousins. The mind boggles. One's imagination can run riot with that image. All the chairs and all the sofas and all the seats on trains and buses would have to be changed.

Human with a tail in X-ray. Image by DALLE.


So what happened? Well, firstly, unlike Tucker Carlson, you've got to believe in evolution to believe in this scientific explanation. In fact, I hope Carlson reads this article because it might make him see sense about evolution. He believes that God created humans and animals under the creationist theory. He says there is no evidence for evolution which is wrong but he believes creationism about which there is certainly no evidence whatsoever. Tucker Carlson is irrational.
"It has long been speculated that tail loss in hominoids contributed to orthograde and bipedal locomotion, the evolutionary occurrence of which coincided with the loss of the tail" - quote from the study - see citation at base of page.

The reason


In summary, a genetic parasite altered a crucial gene related to tail development when our lineage diverged from other primates around 25 million years ago. This alteration ultimately led to the disappearance of tails in apes, including humans. Our tailless state owes its existence to this ancient genetic twist.

In some more detail: over millions of years, DNA undergoes changes that drive evolution. One intriguing element is the Alu element, a repetitive DNA sequence found exclusively in primates. These “jumping genes” can insert themselves randomly into the genome, potentially disrupting or enhancing gene function. In this case, the Alu elements reside in the TBXT gene, specifically within introns (DNA sequences flanking exons). Introns were once considered the “dark matter” of the genome, assumed to serve no purpose. However, when cells use the TBXT gene to generate RNA, the repetitive nature of Alu sequences causes them to bind together.

The researchers discovered two Alu elements in the TBXT gene, present in great apes but absent in monkeys. Remarkably, these elements reside in introns, not in the protein-coding exons. When RNA molecules are generated from the TBXT gene, the Alu sequences bind together, potentially influencing tail development.

Now, that is highly technical and I don't fully understand it but that is the current explanation as to why humans don't have tails. You can boil it down to the way evolution works and the way genetic mutations sometimes arise during evolution which leads to the creation of a different kind of animal and that animal does very well in terms of survival and therefore this alteration to the appearance and physiology sticks around and doesn't disappear.

Bo Xia, is the first author of the study (formerly a graduate student at New York University and now a principal investigator at the Broad Institute).

RELATED ARTICLE: Feline Evolution in Brief.

Study Citation


Xia, B., Zhang, W., Zhao, G. et al. On the genetic basis of tail-loss evolution in humans and apes. Nature 626, 1042–1048 (2024). https://doi.org/10.1038/s41586-024-07095-8


P.S. please forgive the occasional typo. These articles are written at breakneck speed using Dragon Dictate. I have to prepare them in around 20 mins.

Wednesday, 24 April 2024

Tucker Carlson rejects evolution and believes God created us (creationism)

Tucker Carlson is the American commentator and writer who made a fool of himself when interviewing Putin. He was so obviously sycophantic, looking up to the Almighty Putin, Czar Putin as if he were some sort of God. It was embarrassing but it did show the sort of attitude he has about life generally. He clearly thinks Putin is a wonderful leader and probably doesn't object to Putin's illegal invasion of Ukraine.

It's now come to light that Carlson does not believe in the concept of evolution as espoused by Charles Darwin. Darwin's theory of evolution (of natural selection) is almost universally supported by scientists of all colours and persuasions and by the vast majority of educated people who are not religious fundamentalists.

On cell phones click the image to see it larger....


It seems that Tucker Carlson is a kind of religious fundamentalist because he believes that God created animals and humans as per the story in Genesis. No doubt he believes that humans have dominion over animals and can use animals as they wish. This means that they can abuse animals and do whatever they like because animals are there to serve humans. I expect Carson to think those sorts of thoughts.

The man is, in my honest opinion, deluded and needs help. He says there is no fossil evidence that humans have ultimately evolved from single celled protozoans over billions of years.

I think he's correct in that you can't trace a line of fossils all the way from single cell creature to highly complex human. But fossil records provide ample support of evolution. I'm not a specialist about evolution but there is all kinds of scientific evidence which supports the theory.

Here's some evidence summarised:
  1. Biogeography: Darwin observed closely related species inhabiting the same or adjacent territories. This distribution pattern suggested that these species likely descended from a common parent species. The geographical distribution of organisms provided crucial evidence for evolution.

  2. Paleontology: Fossil records revealed a sequence of life forms over time. Transitional fossils, such as Archaeopteryx (a link between reptiles and birds), demonstrated gradual changes between species. These fossils supported the idea of common ancestry and gradual evolution.

  3. Embryology: Comparing the embryonic development of different species revealed similarities. For instance, vertebrate embryos exhibit common features early in development, even if they diverge later. These shared developmental patterns indicated evolutionary relationships.

  4. Morphology: Darwin studied anatomical structures across species. Homologous structures (similar features due to shared ancestry) provided evidence for evolution. For example, the pentadactyl limb (with five digits) appears in various vertebrates, including humans, whales, and bats.

  5. Molecular Biology: DNA and genetic codes reflect shared ancestry. Comparing DNA sequences among species reveals evolutionary relationships. Similarities in genetic information support the concept of a common ancestor.

In summary, Darwin’s theory of evolution is supported by direct observations, homologies, fossils, biogeographical patterns, and molecular evidence.

Back to Carlson...

Carlson says that because we talk of Darwin's theory of evolution that it still remains a theory meaning not proved but he is wrong because in this instance, using the word 'theory' in a scientific context, means that it is solidly supported by evidence and hard science.

Tucker Carlson rejects evolution and believes God created us (creationism)
Tucker Carlson.

Image credit: By Gage Skidmore from Surprise, AZ, United States of America - Tucker Carlson, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=135028856

Respecting Creationists


Of course, I respect the views of others. I respect the views of religious fundamentalists. They have a right to believe what they want to believe. But they are wrong about evolution and about God creating humankind. Religion is a creation of humankind as it makes life more palatable.

Believing in a God


Believing in a God is very helpful in life. No question about it. My mind immediately turns to the number one golfer in the world currently Scottie Scheffler. He is religious and he firmly believes in God. He uses his religion very productively in his golf. It helps to keep him calm and better cope with the pressures of playing professional golf.

His attitude and mentality when playing golf tournament are second to none. They are underpinned by his religious beliefs. Believing in God takes away a lot of the pressure when playing a tournament because the outcome is taken from the golfer and placed into the hands of your God. 

When you hear Scottie Scheffler talk he does so incredibly calmly as he has handed over his life to God which is very calming. Believing in a God removes a lot of the anxiety that one is bound to experience in our day-to-day lives and more so for a professional sportsman when competing.

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P.S. please forgive the occasional typo. These articles are written at breakneck speed using Dragon Dictate. I have to prepare them in around 20 mins.

Monday, 26 February 2024

The domestic cat is NOT weird as stupid newspaper journalists claim

Online newspaper journalists have a tendency to claim that the domestic cat is "weird". It just plain stupid. Domestic cats behave as they instinctively have evolved to behave. They behave differently to humans and from a cat's perspective, no doubt humans behave weirdly. 



In fact human behaviour is far more weird than cat behaviour. Look at what humans are doing to the planet at the moment? They are destroying the planet upon which they rely for sustenance and for all their needs. If that isn't weird I don't know what is.

But a website called Your Tango says that cats are weird and they list 15 facts to prove it. So what are these facts? I will touch on a few of them to illustrate my argument.

Perspiration


The first one they list is that "cats sweat through their paws". What is weird about that?! That's perfectly normal. Cats can't sweat through their bodies because they have a coat which is highly functional. And they keep their coat clean all by themselves without having to go into the shower! Far more practical than human behaviour. 

Also when they groom themselves it helps to cool them through the same scientific process which makes sweating effective: the latent heat of evaporation.

Tasting sweetness


And they add that "cats can't taste anything sweet". So what? Cats are obligate carnivores. They've evolved to eat meat. They don't need to be able to taste sweetness. 

Look, if humans couldn't take anything sweet just like cats there would be much less human obesity. Around 40% of Americans are obese. It is a similar percentage UK residents. This obesity is nearly always caused by overeating and eating the wrong foods including foods high in carbohydrate i.e. sugars. Sugars and salt are addictive to humans.

Ironically, the only reason why domestic cats can be obese (and there are too many obese domestic cats thanks to poor human caregiving) is because of the high carbohydrate content in the unnatural dry cat food that they are given so often. Humans have passed on their obesity to the domestic cat.

Grooming exaggeration


Then Your Tango begins to get things wrong. They add that "cats spend up to half their lives grooming themselves". Wrong! Completely wrong! Cats are fastidious groomers but they don't spend half their lives grooming themselves.

Sleeping exaggeration


And they say that cats spend 70% of their lives sleeping. This is incorrect as well because cats, particularly full-time indoor cats, spend a lot of their time perhaps even more than 70% sometimes of their lives not sleeping but snoozing. That's because they've nothing to do thanks to full-time indoor living and a sterile environment. They are not sleeping in the proper sense. We know this because they leap into action at the slightest activity near them.

DNA


The journalist also adds that domestic cats shed 95.6% of their DNA with tigers. That's probably correct and there is also nothing weird about it at all. It's what you would expect because thanks to millions of years of evolution both the tiger and the domestic cat stem from the same ancient cat-like animal. 

Their evolutionary paths split millions of years ago but their ancient origins are the same. Nothing strange about that. It is all nature, evolution and scientific.

I won't bother to go on because I'm wasting my time. I've made my point. Online journalists need to be more careful and stop using click bait words and tactics. I've seen too much of it; too much stupidity and carelessness.

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P.S. please forgive the occasional typo. These articles are written at breakneck speed using Dragon Dictate. I have to prepare them in around 20 mins.

Sunday, 23 October 2022

Uncontrolled sibling breeding evident in this black cat brigade

The problem of uncontrolled breeding of unowned (and owned cats regrettably) is very evident in this picture of a group of black cats in the US on a country road.  They all look the same down to the spot of white on their chest on some individuals. 

RELATED: How fast do cats breed?

They are all closely related, parents and siblings.

The capacity of the domestic cat and domestic cats turned stray and feral to procreate is one of the big challenges of humankind. 

RELATED: Female feral cats avoid inbreeding in colonies.

Uncontrolled breeding in a colony of feral cats all of which look the same or very similar
Uncontrolled breeding in a colony of feral cats all of which look the same or very similar. Image: see embossed credit.

Apparently, we are not entirely capable of controlling it despite widespread spaying and neutering. 

A failure to sterilise is the cause of cat hoarders ending up in a massive mess and cruelly neglecting their cats. The opposite is achieved with well manages TNR programs supported by the local authority.

The benefits of controlling cat procreation are seen in TNR.

A tiny minority of cat people believe that a female cat needs to have one litter before feeling whole. This single incorrect superstition is the cause of hundreds of thousands of unwanted cats leading to many feral cats and in turn plenty of feline misery.

Some human thoughts are really silly and dangerous.

There are some interesting and technical downsides to universal spaying of female cats and neutering of male cats.

The most docile and friendliest cats are going to be captured and neutered while the wildest and meanest avoid people and are harder to capture and sterilise. This could lead to pushing the cat's evolution away from where we want it: more adoptable cats.

Also, if there were 100% sterilisation and no breeders the domestic cat would eventually become extinct. Not much chance of that bearing in mind that there are an estimated up to 500 million domestic, stray and feral cats on the planet.

Ingrid Newkirk, the co-founder of PETA would probably like the gradual extinction of the domestic cat as she is firmly against cat domestication. 

Click on this link to read four of her quotes and some comments on them.

Monday, 9 May 2022

Cat coats tabby - all about, nothing left out

tabby cat
Cat Coats Tabby - Mackerel Tabby cat Chihiro - photo copyright fofurasfelinas reproduced under a creative commons license

Introduction - history


The tabby markings/color
is probably the most common, in either domestic cats or wild cats (e.g. Scottish wildcat). When cats breed randomly over a long period of time, apparently the coat color and pattern tend towards brown mackerel tabbies with green eyes (the most common "phenotype" - meaning the observed expression of the genetic make-up).

RELATED: Why are tabby cats so common?

This indicates a genetic predisposition towards what is probably the most efficient coat color/pattern in respect of the cat's survival. There are three tabby patterns: the classic blotched pattern, the striped or mackerel pattern, and the spotted pattern. The Bengal cat for example can have a spotted tabby or blotched coat, while the Egyptian Mau has a naturally occurring spotted tabby coat - the only naturally occurring spotted domestic cat it is said. 

The agouti ticked coat (the Abyssinian cat has the classic ticked coat) is a special kind of tabby coat. 

The Abyssinian has a special tabby coat. There are few markings unlike the usual tabby coats that can be spotted or blotched. This picture shows the banded hair strands. This photo is published under a Wikimedia Commons license. Author: Martin Bahmann 


As mentioned, you can see the tabby coat in wild cats such as the African wildcat and American Bobcat for example. However, I don't recall seeing a wild cat with what the cat fancy calls the "blotched" tabby coat. All wildcats appear to have spots and/or stripes or no tabby pattern. The blotched tabby appears to be a creation of the cat fancy or at least it has been "developed" and enhanced by the cat fancy (cat breeders). 

Tabby cat from Ancient Egypt (not far from Saudi Arabia) from 1500 CE. Picture in public domain.
Tabby cat from Ancient Egypt (not far from Saudi Arabia) from 1500 CE. Picture in public domain.

Dr. Desmond Morris, the great zoologist and writer, tells us that it is believed that blotched tabbies arose first in Britain in the Elizabethan era. As you can see, they arrived very late during the evolution of the domestic cat. For the first 2,000 years or so or more all tabby cats were spotted/striped (broken stripes) tabbies and all domestic cats were spotted tabbies. And therefore, all domestic cat during the era of the ancient Egyptians were spotted/striped tabbies.

Dr. Morris says that the blotched tabby became a winner. In other words, a favourite and he is not sure why they did so well. Perhaps they were more healthy or more fertile than the other forms of tabby cat or perhaps they had an unusual level of aggressiveness or assertiveness. Perhaps people just like them and informally bread them?


Development of the blotched tabby domestic cat. My thanks to the scientists of the study:  The palaeogenetics of cat dispersal in the ancient world.


Today, the blotched tabby is the most common form of tabby coat and the striped tabby has gone into somewhat of a decline. Of course, nowadays the tabby coat is just one of many types of coat that have evolved during domestic cat evolution. However, Dr. Morris reminds us that genetically and in reality all domestic cats are tabbies. If they don't appear to be tabbies it is because the tabby pattern is masked by the other non-tabby colours.

African wildcat compared with domestic cat. Image: MikeB from images in the public domain.

Of course, the tabby pattern comes from the original domesticated wildcats. The North African wildcat has a week tabby pattern. And if we want to visualise the early domestic cats all you have to do is look at today's African wildcats. From paintings created in ancient Egypt we see that the Egyptian cats had light or broken stripes. When they were exported over thousands of years to other parts of the world including Europe, the cats began to hybridise with their European counterparts and the result was a full-tabby coat.

Tests have shown that when the week-tabby European and African wild cats were experimentally crossed the hybrid kittens developed coat patterns which were much closer to the full-tabby pattern of modern domestic cats according to Dr. Desmond Morris. I have quoted him verbatim.

Ginger blotched tabby
Ginger blotched tabby. Photo: Pixabay.

All tabby cats have the classic M marking on the forehead in varies styles and disguises.

An example of a purebred and pedigree tabby cat would be the American Shorthair.  This breed looks particularly stunning in silver tabby. Another example of a beautiful purebred Maine Coon tabby can be seen by clicking on this link. The tabby pattern is often seen in Maine Coon cats. The cat associations allow a wide range of Maine Coon cat coat types (you'll see a great tabby MC on this link). There are some classic tabby patterns on wild cats. A good example is the tabby coat of the wildcats. These cats look very much like domestic cats as they are the wild ancestor of today's domestic cat.

Origin of Name

It is thought that the word, "tabby" originates in the appearance of silk sold in Baghdad (the Attabiyah region). This region must have been known for selling silks that had a striped appearance (watered - waved - silk) as incorporated into the name. Attabiyah is reference to the Latin attabi, and later the French tabis, which means, as I understand it, watered silk. As the striped and marbled tabby cats have the same general appearance, the word "tabby" was used to describe the coat.
cat coats tabby - tabby cat
Cat Coats Tabby - Mackerel Tabby cat Chihiro - photo copyright fofurasfelinas reproduced under a creative commons Attribution-NonCommercial-NoDerivs License

The Genes

As mentioned, the wild cats have tabby coloration and patterns and the domestic cat is descended from the wild cat (see a comparison between the Scottish wildcat and domestic tabby). The pattern has 2 elements to it. (1) There will be a group of hairs in which the individual hairs have bands of color running horizontally up the hair strand. One band will be yellow and the next black. These hairs form the background color upon which the pattern is overlayed by the second group of hairs. The commonly spoken of "Agouti" gene (A) creates this banding pattern on the hair shafts. The banding on the hair shaft is due it is thought to a reduction in the production of the pigmentation granules or the production of a different and yellow pigment. This results in fewer granules that are spread more thinly throughout the hair follicle to give the beige/yellow looking color.

The pigment producing the black band in the hair shaft is called eumelanin and the yellow pigment is called phaeomelanin.

Tabby Hair Strand. Image: MikeB.


If the band near the surface is beige you get the light brown broken effect and if the black banding is near the top the black is broken up by the beige banding lower down. (2) The other group of hairs will be black because the yellow banding referred to above will have been reduced (repressed) to the base of each hair or removed entirely. This group is seen as the spots or stripes or blotchy patches of black or brown that forms the patterns seen in the pictures. This effect is a result of the presence of the Tabby gene (Mc/mc), which is present in all cats and so are the markings but often sufficiently suppressed as to be invisible.

I know a small classic tabby that has also solid black hair in swathes, and also black hair with one band of beige near the surface which creates a speckled look on black. All these combinations are mixed together in various proportions and in varying sized clumps to produce the tabby pattern. The pattern that we readily see is due to the alternation of solid color (black fur) with the banded fur to create a pattern as mentioned above. It is the Primary Tabby gene (Mc) that dictates how the pattern will shape up for the individual cat.

tabby cat
Cat coats tabby - Tabby cat. This is a great photograph of a tabby cat. I just had to put it on this page. It is reproduced under a creative commons license.

There are several varieties of tabby markings and of course as mentioned an almost inexhaustible spectrum of colors, contrasts and pattern variations particularly in purebred cats where the appearance of the cat is of paramount importance.

Update 12th January 2011: See an article on red tabby cats and a nice picture of a Maltese red tabby.

Torbie

The torbie is a mix of tabby and tortoiseshell. Here is an example:

Gemma: Torbie Siberian Cat. Photo copyright Helmi Flick

Read about torbies by clicking on the link below:

  
Tabby Cat Picture

There are a lot of tabby cat pictures on this page! People search for "tabby cat picture" so here is one of the best of a rescue cat by Giane Portal on Brazil. This is a classic blotched grey tabby cat - perfect example. You can see an orange tabby cat picture or two on this page.

Dominique
Dominique - photo copyright Giane Portal

Mackerel Tabby

silver mackerel tabby cat
Cat Coats Tabby - Silver mackerel tabby cat - photo copyright Helmi Flick

red-and-cream-mackerel-tabby-cats
Cat Coats Tabby - Cream and red mackerel tabby cats - photo copyright Helmi Flick

red-mackerel-tabby-cat
Cat Coats Tabby - Red mackerel tabby cat - photo copyright Helmi Flick

brown-mackerel-tabby-cat
Cat Coats Tabby - Brown mackerel tabby cat - photo copyright Helmi Flick

blue-and-brown-mackerel-tabby-cats
Cat Coats Tabby - Blue and brown mackerel tabby cats - American curl cats - photo copyright Helmi Flick

The type we probably are most familiar with is the mackerel, stripped tabby. This is considered the wild type of tabby pattern. The genotype (the genes producing the black tabby coat) is A (agouti) + B (black) + D (dense coloration) + Mc (tabby gene).

Breeders like high contrast striping that is nice and evenly spaced and the stripe should be continuous. The Toyger has this. The Toyger also has a beautiful base or ground color that is incredibly warm (orange almost). The base color comes from the color of the agouti band on the individual hair strand. The warming up of the ground color is due to selective breeding in modifier genes (rufus modifiers). Click on the link to go to a pictures of cats.org videos of cats many of which are fundamentally tabby cats (YouTube, channel is broadsurf the YouTube name of Michael at Picture of Cats).

Classic Tabby

blue classic tabby cat
Blue classic tabby - photo copyright Helmi Flick

red classic tabby cat
Red classic tabby - Maine Coon - photo copyright Helmi Flick

cream classic tabby cat
Cream classic tabby - photo copyright Helmi Flick

brown classic tabby cat
Brown classic tabby - photo copyright Helmi Flick

silver classic tabby cat
Silver classic tabby cat - This as you might have guessed is an American Shorthair cat. I have a post dedicated to the American Shorthair tabby cat. The silver is due to the Inhibitor gene I, which inhibits the production the yellow Agouti banding leaving the black to contrast more starkly with a gray/silver background.

The genotype (the genes producing the black tabby coat) of the classic blotched tabby cat is A (agouti) + B (black) + D (dense coloration) + mcmc (tabby gene). The difference to the mackerel tabby is the existence of the mc allele (allele = one of a pair of genes).

Spotted Tabby

brown spotted tabby cat
Brown spotted Tabby - Bengal cat - - photo copyright Helmi Flick. Bengal cats are known for a very high contrast marbled pattern, see some superb examples by clicking on this link. Spots are another form of tabby pattern. You can see this beautifully expressed in the Bengal cat and/or, for example, the Ocicat.

blue spotted tabby cat
Blue spotted tabby cat - - photo copyright Helmi Flick
cream spotted tabby cat
Cream spotted tabby - Exotic Shorthair cat - photo copyright Helmi Flick


silver spotted tabby cat
Silver spotted tabby - an example of the presence of the Inhibitor gene I - a Bengal cat - photo copyright Helmi Flick.

Research is still being carried out on the genetics behind the spotted tabby coat. It may be due to a modifier gene on the mackerel tabby. The striping of the mackerel tabby can break up and if that is captured and bred into the cat you'll get spots. In the Ocicat it seems that the effect is due to a dominant modifier of the blotched classic tabby pattern. Click on the link to see a video of the Ocicat on YouTube (this video is part of Pictures of Cats.org)


Ticked Tabby - Abyssinian Tabby


silver-ticked-tabby
Cat Coats Tabby - Silver ticked tabby - Abyssinian cat - photo copyright Helmi Flick

red-ticked-tabby
Cat Coats Tabby - Red ticked tabby - photo copyright Helmi Flick

brown-ticked-tabby
Cat Coats Tabby - Brown ticked tabby - photo copyright Helmi Flick.

Robinson's genetics says that the gene that produces the Abyssinian ticked coat is not the same gene as the tabby gene producing the classic and mackerel. They call it the "ticked gene". The authors say that the Abyssinian cat's appearance is a mutation of the normal tabby. The tabby pattern occurs on the head, legs and tail and very faintly elsewhere on the body. Breeders like to reduce the pattern further by careful breeding. The most frequently seen Aby color is the ruddy (red) - middle picture above - called the "usual". Breeders breed in a warmer color.

The full set of genes producing the well known Abyssinian coat are: AA (Agouti) - B (black) - D (dense coloration) - TaTa (ticked gene).

The tabby cat locus maps to the feline chromosome B1. It seems possible that the tabby gene has a homologue (common evolutionary origin) on human chromosome 8 or 4. (src: http://www.pubmedcentral.nih.gov/)

Interesting

This is an interesting bit of information about the tabby cat as camouflage, which comes from Desmond Morris's book "Catwatching". It had been proposed by a nineteenth century naturalist (I presume) that when a tabby cat is curled up she/he looks a bit like a "coiled snake". Once again this is a form of mimicry, one of a number of examples of the cats mimicry of the snake as an act defensive. Read about a cat hiss as another example.

A Torbie is a mixture of tabby and tortoiseshell. An example of tortoiseshell is the black tortoiseshell or just plain old tortoiseshell cats (this page has great pictures). Some people think the tabby cat is a cat breed.


See a Tabby Persian cat picture by Helmi Flick

Cat coats tabby - Photographs not captioned are copyright Helmi Flick and as follows:
  • Top is a classic tabby
  • 2nd is the mackerel tabby
Cat coats tabby - Sources:
  • Messybeast
  • Cat Fanciers
  • Beth Hicks
  • Robinson's Genetics
From Cat Coat Tabby to Cat Facts

Friday, 9 July 2021

Are domestic cats related to lions and tigers?

Yes, domestic cats are related to lions and tigers and all the other cats because they all started off at the same source. This is about evolution and taxonomy. But you have to go back about 40 million years to Miacoids (miacids) which appear to be the first cats on the planet although they did not look like modern day cats. 

Tiger and domestic cat. Collage: PoC.
Tiger and domestic cat. Collage: PoC.



It is currently believed that from that start all the cat species evolved in different places and at different times. Miacids evolved into the Proailurus (a civet/cat creature) and that creature evolved into prehistoric cats which walked on their toes like modern day cats. 

An example was a species called Pseudaelurus. This creature was the size of a modern-day cat. It evolved into two main groups one of which was Schizailurus which in turn evolved into the Felidae (the family of cats). Martelli's cat was a species which inhabited Europe about 2.4 million years ago and which is believed to be the ancestor of today's wildcat, a species of cat which is still present in Europe. Apparently the first modern day cats were cheetahs.

Cat history from the start to modern day
Cat history from the start to modern day. Cat History For Kids. Credits: Landscape of N.America 10m years ago Wikimedia Commons author Jay Matternes. In public domain USA. Fair use pleaded. Pseudaelurus in public domain USA and fair use pleaded. USA 1945 by army.arch creative commons. Snowshoe cat copyright Helmi Flick. Note: there is one small deliberate mistake in the picture. Can you spot it and leave a comment?

You have to believe in evolution to believe that domestic cats are related to lions and tigers. But science supports evolution. It is through evolution that domestic cats are related to lions and tigers. Domestic cats are very, very similar in every respect to lions and tigers. There is not much difference which is apparent because they both look like cats! There's a massive size difference but the domestic cat, in its mind, thinks just like a tiger or lion. And their behaviour is incredibly similar. That alone tells you that they are related.

If you want to know a bit more about big cat history you can click on this link. And I cover the evolution of the cat species in a simplified way on this page (click link please). The science of taxonomy which is the classification of the species is evolving itself. It was enhanced through scientific knowledge of DNA. Before DNA scientists simply observed an animal undecided whether it was similar to another animal and therefore classified it as part of a species or subspecies. That proved to be imprecise whereas DNA testing is very precise because it gets to the core of the issue.

Sunday, 6 June 2021

Do tigers live in the Amazon rainforest?

Categorically no, tigers do not live in the Amazon rainforest! The big cat which is the top predator in the Amazon rainforest is the jaguar, which is not much smaller than the tiger. Why are there no tigers in the Amazon basin? It's just a question of evolution. The tiger was first created through evolution in Asia and I guess there was no landmass connecting Asia with the Amazon basin millions of years ago and therefore there was no possibility for the tiger to migrate across that landmass to what is now South America.

Elusive Bengal tiger in Kanha Tiger Reserve, India. Photo: in public domain.

READ MORE ABOUT THE TIGER

It is the same reason why there are no wild cats on the Australian continent. It's just down to a water barrier between the area where the wild cats evolved, which in this instance is the Far East, and the Australian continent. If Australia was connected to the Far East there would be a range of wild cat species living in Australia today. If there were perhaps the Australians would like feral cats more! They hate them judging by the numbers that they kill.

It is also the reason why there are no tigers in Africa and on that continent the lion is the top predator. The tiger is slightly bigger on average than the lion, by the way, but it is said that the lion can beat the tiger, on average, in a fight.

Once again, going back millions of years when the tiger first evolved into a cat which looks like today's tiger there was no possibility for that animal to migrate to Africa because of a water barrier and therefore all the tigers are in Asia beginning with India and going all the way across to China and the Russian Far East, where the Siberian tiger lives in very small numbers by the way (500).

There is a range of tiger subspecies but some have become extinct because of human activities. The Bengal tiger is the dominant species of tiger in the world but even those are limited to about 3,500 in total population size but we don't know exactly how many there are because it is difficult to count them through scats and camera traps records.

Saturday, 8 May 2021

10 million years ago the largest cat alive was a 600 pound sabre-toothed cat species

Scientists have identified a giant new sabre-toothed cat species which they believe was present on the planet in North America between 5 and 9 million years ago. It had an estimated body mass of 604 lbs (274 kgs) but it could have been larger. The long bone of the arm (humorus) was 1.4 times longer than that of the modern day lion.

This is a sabre-toothed cat but not the one mentioned. Photo: Getty.

They decided that this super-sized cat species attacked rhinoceroses which were abundant in North America at that time. They would have also preyed upon camels and sloths both of which would have been much larger than today's species. As yet, the scientists do not know how this species of cat fits in with the others in terms of evolution and taxonomy.

They said that it was known there were giant sabre-toothed cats in Europe, Asia and Africa and now North America have their own. They used digital images and specialised software to find similarities from the relics of other cat species. They say that they discovered many specimens of this big cat in museums in western North America. Comment: perhaps they had not realised the significance of them until now. They used these other specimens as a basis for their analysis which helped them to identify this new felid.

Associated: Sabre-toothed cats were endurance hunters in complete contrast to today's stalkers and dashers.

Sunday, 28 February 2021

How domestic cats came to be in a nutshell

Evolution of the species. How domestic cats came to be in a nutshell.
Evolution of the species. How domestic cats came to be in a nutshell. Screebshot.

Some people want to know how domestic cats evolved to where they are today. To answer the question you have to believe in Darwin's theory of evolution as set out in his book On the Origin of Species published on Thursday, 24 November 1859. If you believe in his theory as opposed to creation by a God (creationism) then you have to study the theory of evolution to fully understand it. 

Remember that life emerged on Earth 3.5 billion years ago so evolution is a slow process. That's way we have the species we have. It took millions of tiny changes. Also the first early human ancestors orginate from 3.5 million years ago.

Darwin's On the Origin of Species
Darwin's On the Origin of Species.


This will allow you understand how domestic cats came to be - the first part of the story. The video below explains it quite nicely I think. It is quite complicated. 

Image: MikeB.

You can click here too if you want to read about the evolution of the family of cats.

The theory of evolution explains how natural selection produced the family of cats. There are about thirty-six species of cat, one of which is the domestic cat. All the others are wild cat species. The domestic cat is essentially a domesticated North African wild cat.

Over the ten thousand years of domestication of the North African wild cat, the species evolved from being striped tabby cats to a wide range of coat types. This happened naturally and then people intervened through formal selective breeding or artificial selection since about 1850. Although there would have been some selective breeding by people on an ad hoc basis in the early development of the domestic cat as they preferred coat types.

Through artificial selection, as carried out under the auspices of cat fancy (cat breeders who create purebred cats of a certain breed for cat shows and for sale) about 104 cat breeds were created, as an absolute maximum. To these purebred cats you have to add the vast majority of domestics cats namely random bred cats. Also we must not forget the cats who should be domesticated but are feral (wild), the feral cats.

Random bred cats are still evolving through natural selection. That, in a nutshell is how domestic cats came to be...!

Tuesday, 15 November 2011

Why are cats' tails so long?

Are cats tails so long? It is all relative and subjective. But some cat's tails are longer than others. If the cat is a domestic cat there is no pressing reason why his or her tail should be longer than that of another cat other than the physical characteristics of the cat as dictated by his genetic makeup (genotype). There will be no demanding functional need for a long tail.

The situation is different for the wild cats. You will see long, thick, heavy and well insulated tails on cats that do a lot of high risk climbing and maneuvering. Wild cat species that come immediately to mind are the snow leopard, margay and clouded leopard.

I believe what needs to be stated is that the length of a cat's tail has been dictated by evolution over millions of years. The tail is a perfect length for the function that it needs to perform which as mentioned below is to help a cat balance when performing manoeuvres which are tricky at high elevations. For example, walking along a branch of a tree for a domestic cat or a tree-dwelling wild cat species (margay). Because evolution has a sort of perfection about it you cannot state that the tail is so long or too long or too short. It is a perfect length for its desired primary function.


A secondary function is as a signal to another cat that the approaching cat is friendly. This is when the tail is placed in an erect position called "tail-up". Another secondary, inadvertent function, is that it signals an indecisive mind. When the mind flicks between two possible decisions the tail follows as if metaphorically speaking it is keeping the cat's mind in balance.

Snow leopard tail - cropped image to highlight tail
You won't see a better tail. Photo: by Marit & Toomas Hinnosaar

The snow leopard has perhaps the most impressive of tails. It is far longer and thicker than anything seen on a domestic cat relative to the size of the cat. This is because the snow leopard spends a lot of its time on 40 degree rocky slopes. And the tail is needed to assist in balance. The other two are tree dwelling cats.

This requirement applies to all cats. The cheetah, a ground dwelling cat uses its tail for balance in maneuvering on the ground when chasing prey.The serval has a relatively short tail. The serval is very much a terrestrial cat.

Domestic cats use the tail for balance too, but also for body language communication. See for example: Tail up.

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