Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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How likely is it that Earth has millions of different species?

I know that the probability of life existing on a habitable planet is pretty slim. But, how likely is it that it hapenned millions of times in the same planet? Or was it only a few species that ...
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4answers
297 views

How come most animals never seem to evolve over millenia?

People often say, including those with extensive knowledge in biology, that a certain species of animal will evolve in one way or another: 1.From changing environments. 2.Mutations. 3.Possibly even ...
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158 views

Is there any genetic similarity that defy evolution theory?

For example, say species A is common ancestor of B, and C. Species B is a common ancestor of D and E. We would expect that there will be more genetic similarity between D and E than D and C. And ...
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1answer
170 views

What are the visual, behavioral similarities and differences between Yellow Fever Mosquito (Aedes aegypti) and the Tiger Mosquito (Aedes albopictus)?

The Tiger and Yellow Fever Mosquito visually look very similar. Recognizing the difference is important for tracking and controlling the spread of Yellow Fever, Dengue fever and other diseases. ...
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2answers
531 views

Are there genetic similarity between humans and pigs that don't exist in chimps?

Chimps are our closer relative. Any genetic similarity between humans and chimps must exist on the common ancestor. Pig branch out sooner. So, any genetic similarity between humans and pigs must be ...
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1answer
43 views

Is there any evidence telling us what the oxidation state of early earth's atmosphere was?

I ask this question in relation to the origin of life. I realise it would probably be better suited to a geology stack exchange, but it does not yet exist. The Miller-Urey experiment gives a lab ...
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1answer
93 views

Does avocado and orange have a common ancestor?

While I'm eating my orange, I felt as if I was eating avocado. It might be genetic manipulations perhaps but it made me think if they have a common evolutionary ancestor. Is there?
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2answers
777 views

The number of nipples (breasts) a species has?

Only mammals have mammaries and mammary glands. What evolutionary factors determines the number of mammaries (nipples/teats/breasts) a species has? Is it always an even number?
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1answer
72 views

Chemoautotrophy in large organisms?

The major nutritional mechanisms include chemoautotrophy, heterotrophy (including parasitism and saprotrophy) and photoautotrophy. All of these modes of nutrition developed first in prokaryotic ...
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1answer
450 views

Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
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2answers
156 views

Effect of zero selection (pressure) on the population health

Evolution naturally produces better features: stronger muscles, teeth and minds. Killing the weakest, evolution wipes defective genes out of populations. The mutations are necessary for advance. ...
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1answer
108 views

Natural enemies boost deep evolutionary fitness?

"Two species that reduce one another's fitness on microevolutionary (short-term) timescales can increase each other's macroevolutionary (long-term) fitness" Opinions? Intuitive Examples: ...
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1answer
51 views

Are there cannibalistic k-selectors?

My understanding of r- and k-selectors does not go deeper than the wikipedia article. I understand k-selectors to be creatures that put tendentially more effort and energy into rearing their ...
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1answer
137 views

Is there a comprehensive database of fossils (with images) online?

Not sure if this is the best stackexchange to ask... I have not been able to find a decent database of fossils on the web, does one exist? Here are some of the links I have found through Wikipedia ...
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1answer
60 views

How much can you learn about species variation from a skeleton?

I just read about the discovery of the 1.8-million-year-old human skull in Georgia, and how it suggests that early humans were all one species instead of distinct ones. Would an archaeologist ...
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1answer
170 views

What is the most recent non-primate ancestors of humans?

If we go down the evolutionary tree of humans, (Homo sapiens, Homo erectus, ...), what will be the first non-primate ancestors?
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3answers
1k views

Does Darwin's Theory of Evolution refute Terence McKenna theory “Stoned Ape” theory of human evolution?

I haven't read it but I'm asking for a quick answer. As far as I know, Terence McKenna's theory of evolution in humans main concept is that a hominid has tried in their diet psilocybin mushrooms, and ...
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1answer
60 views

Does the existence of one species imply the existence of many other?

Reading one of Sir Arthur Clarke's scifi stories, I came across a statement something to the effect of, existence of a single species automatically implies the existence of many other species. So ...
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2answers
663 views

Why have humans evolved conciousness?

Why did humans/animals evolve to become self-aware of their own thoughts. That is, why don't humans act and compute like a machine, or walking zombie. In my mind, such creatures would still be as ...
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2answers
209 views

Why is there such an argument about evolution?

DISCLAIMER: I am a Christian, although I happen to believe that some form of guided evolution via natural selection is God's mechanism for creation. Now to my question, which is related to my ...
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1answer
152 views

What is the evolutionary advantage of regret?

Some motivational speakers may say that regrets are only useful to learn something from. What are the other advantages?
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3answers
3k views

Why does human facial and head hair continue to grow?

Many people can grow extremely long head hair and facial hair. Are there evolutionary theories as to why this is the case? It seems like having long hair could be a disadvantage, and extremely long ...
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2answers
123 views

Won't natural selection miss the overall minimum of a function?

Suppose we have a population of about 1000 with an environment that does not change a lot (e.g. the atmosphere is more or less the same) and we leave this population to evolve. From what I understand ...
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3answers
95 views

How to define “evolution”?

The standard answer to: what is evolution? is: It is a change in allele frequency over time! I believe a complete definition should encompass the following concepts: mutations copy ...
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1answer
113 views

Why insects are so small compared to mammals?

I was wondering what biological limitations make the dimension of the insects small compared to the dimension of the mammals. I know in other eras insect were bigger!
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2answers
129 views

Which statement about phenotypic plasticity is false?

This was a test question, and I'm not too sure about the answer. Which statement about phenotypic plasticity is false? a. Because the plasticity of a phenotypic trait may be costly to maintain, it ...
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322 views

What does fitness really mean?

Fitness is certainly the most important concept in the theory of evolution. My question does not have to do with practical measures of fitness but with the theoretical definition of it. I am a bit ...
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1answer
211 views

Genetic variation and sensitivity of wild cabbage

1: Is it true that the genetic variation of kale plants is smaller than wild cabbage? I think so, because of human selection of the kale plants. 2: Are broccoli and cauliflower more ...
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1answer
1k views

How did giraffes develop their rete mirabile failsafe?

Giraffes, being one of the tallest mammals in the world, have a failsafe called rete mirabile to prevent them from dying from excessive blood pressure while lowering their head.[1] Due to their long ...
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1answer
74 views

Which mountain range was formed first (historically) and which the pedigree is correct?

Source 1: Source 1 shows a map of a particular area. In this map you will find the mountain ranges 1 and 2, the species P, Q and R. Two possible pedigrees of the ancestral history of the species ...
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1answer
314 views

Why were dinosaurs not as smart as we are?

According to http://en.wikipedia.org/wiki/Dinosaur, Dinosaurs were the dominant terrestrial vertebrates for 135 million years. They had a lot of time to evolve. My question is: why were dinosaurs not ...
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2answers
107 views

Examples of virus originated from a living system

Do you know some examples of virus or a viroid (or a prion) that originated from a known living organism? How does the virus/viroid/prion lives? Does it paratize the organism from which the virus ...
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0answers
23 views

What is the origin of viruses? How could they get both living and non-living characteristics? [duplicate]

I read that viruses are called intermediate between living and non-living particles. Well, if so, then where did they originate from? From living or non-living? If they originated from either living ...
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0answers
31 views

Is there an evolutionary advantage for hamsters throwing up food when scared? [closed]

My hamster throws up food when scared, and from a general Google search it seems that other hamster-keepers experience the same thing. Why do hamsters do this? What advantage does it serve - now and ...
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2answers
176 views

Eusociality and Natural selection?

Eusociality, particularly focusing on the presence of certain altruistic sterile organisms within the social set-up creates questions as to why would the process of natural selection have favoured the ...
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1answer
488 views

Could humans and chimpanzees hybridize?

In some cases two species can hybridize. For example, Tigers and lions can hybridize to produce "Ligers". Would it also be possible for humans and chimpanzees (or any other species) to hybridize ? ...
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1answer
65 views

Historical recovery from mass extinction events

Is there a way to generally characterize how species "regrew" after the various mass extinction events happening periodically from 450 Ma to 65 Ma. Would the surviving species just start back where ...
2
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1answer
116 views

The concepts of relatedness - Hamilton's rule and kin selection

Here is a quotation from this wikipedia page The relatedness parameter (r) in Hamilton's rule was introduced in 1922 by Sewall Wright as a coefficient of relationship that gives the ...
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1answer
57 views

Who was the first to talk about evolvability?

"Evolvability is the capacity of a system for adaptive evolution." (source) There are several other definitions though: Who was the first person to use the word "evolvability"? Who was the first to ...
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0answers
191 views

What are the ESSs among hawks, doves, retaliators, bully and prober retaliators?

In his book "The Selfish Gene", Richard Dawkins says that retaliator emerges as an evolutionary stable strategy. But I think dove is also a kind of retaliator and so if dove increases, the hawks and ...
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1answer
116 views

Evolutionary Cell Structuring

I'm a total novice when it comes to biology, and I'm really just looking for an answer to a question that has been posed to me by people who deny evolution fervently. Evolution dictates that we've ...
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3answers
590 views

How does the modern theory of evolution solve these apparent problems? [closed]

I hold to the truth of Evolution, but I've encountered several problems with it, that I can't answer, and I can't find an answer for, despite much research. If would be great if anyone can answer ...
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2answers
4k views

Why is glucose our primary source of energy?

Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
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1answer
273 views

Empirical evidence for species selection

Do we have any empirical evidence in favor of species (or lineage) selection? Do we know some cases that can only be explained (or seem to be only explained) by lineage selection? What are today the ...
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2answers
149 views

Why is selfishness the 'obvious' strategy?

Thinking of behaviours an organism can adapt, at the very base an action can always be either selfish or altruistic (cooperative). Usually, selfish behaviour is assumed to be the preferred choice and ...
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2answers
282 views

Why are humans and almost every species on earth symmetrical?

I admit I'm not very learned on the subject of evolution, I just started researching it for myself about a week ago. One of the things that I don't understand is why humans and almost every other ...
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1answer
99 views

What are uses of fossils? [closed]

What are the geological uses of fossils and how could it be utilised? From The Institute for Creation Science: Fossils are typically found in sedimentary rock, almost all of which were originally ...
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1answer
42 views

Variation in MHC in humans

What evolutionary process lead to so much variation in MHC? What is the advantage of having such variation?
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5answers
272 views

Is evolution true as Darwin said? [closed]

I was telling the theory of evolution to my friends. But they asked me for the proof. They said, we are not seeing any such transition species at present. Neither we have such evidence for evolution. ...
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2answers
1k views

Genetically speaking, are dogs exactly similar to humans and chimps both?

Richard Dawkins mentions in his book The Greatest Show on Earth that dogs are exactly similar to both humans and chimps. Supposing that a cell contains the genetic similarity between 2 species, he ...