are the horse and chicken related?

[kevinnnnni]

according to the amino acid sequence, the horse and chicken are different only by one amino acid? does this mean that they are related through evolution? why or why not?

[mith]

That statement is false. They might differ in one AA perhaps according to one gene, but certainly not in every gene.

[Darby]

You could answer yes or no in my class - it's the rationale you give that would be the important part.

But I suspect you'd be well-served by going with "yes," and getting into how related organisms have homologous proteins...

[Anaximenes]

Like all members of the animal kingdom, they must share a distant common ancestor (they both have what is known as eukaryotic cell structure). They're related in the same sense that all modern animals, plants and fungi are related - very distantly. At some stage in primeval natural history, a single species would have sired both the animals which would evolve into chickens and those which would evolve into horses.

I'm not completely sure, but I'd hazard a guess that the common ancestor would have been a primitive dinosaur. Aves (birds) and mammals are both descended from dinosaurs as far as I know.

[alextemplet]

Mammals are not descended from dinosaurs but from a family of reptiles that was closely related to the earliest ancestors of the dinosaurs. This would most likely put the common ancestor of chickens and horses in the early Triassic period.

[Quasarsphere]

At some stage in primeval natural history, a single species would have sired both the animals which would evolve into chickens and those which would evolve into horses.

And ultimately, a single individual, yes?

[Darwin420]

Yes some organisms are closer related to others, BUT keep in mind according to DNA sequences ALL OF US came from A SINGLE ancestor where we over a periods of time diverged.

"In the study of early life on Earth, one name towers above the rest: LUCA. LUCA is not the name of a famous scientist in the field; it is shorthand for Last Universal Common Ancestor, a single cell that lived perhaps 3 or 4 billion years ago, and from which all life has since evolved. Amazingly, every living thing we see around us (and many more that we can only see with the aid of a microscope) is related. As far as we can tell, life on Earth arose only once."

[Darby]

It might be more useful to think about the descent being from a single population rather than a single individual - evolution acts on selection of individuals, but surviving individuals recombine features and the population (kind of as an "average individual") changes over time.

[alextemplet]

Has it ever been established with certainty that all life on earth descends from a single cell? Isn't it possible that whatever caused the first life to arise on earth actually gave rise to several organisms, each of which may have led to a different form of life? Or perhaps, through DNA exchange and recombination, every organism that lived on the early earth became our common ancestor? We might not share one common ancestor but several.

[Darwin420]

yea, your point makes sense as well and I consider that a possibility as well. "Has it ever been established with certainty that all life on earth descends from a single cell?" - Alex, virtually nothing in science is established with certainty. The more I learn about biology and evolution the less I know. GOD DAMN, BIOLOGY IS A COMPLEX DISCIPLINE.

[phamquocdat41191]

(sorry if my english isn't good)
good question
of course they are related, every organisms are related. but your statement proves nothing but show that these two kind of animal share the same evolution from unicellular to multicellular. besides, it is just one amino acid sequence, it can not prove that horse and chicken are related nearly
here is one of suprising number, the percent of difference between amino acid in hemoglobin in human's blood and dog's blood is only 16.3%. nonetheless, never think about that human and dog are related nearly.

[JorgeLobo]

only by marriage