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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Living organisms with properties similar to both plants and animals? [duplicate]

Is there any example of currently living organisms that shows close resemblance to both being a plant and an animal? What is the plant with the closest possible resemblance to animals, and What is ...
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0answers
69 views

Why did animals evolve genders? [duplicate]

The majority of animals have two genders, and both are needed in reproduction. It seems like it would be more advantageous for creatures to be hermaphrodites, since they could mate with any member of ...
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2answers
97 views

Can humans' ability to dive with only breathing modifications tell us anything about our evolution?

Can humans' ability to dive with only breathing modifications tell us anything about our evolution? For example, it is possible to imagine a human anatomy that would be destroyed by the pressure of a ...
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8answers
611 views

How does the creative process of Biological Evolution work?

In order for nature to go from microbes to man, there needs to be new information. Where does this new information come from? It is understood that Evolution basically involves three elements. ...
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5answers
285 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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3answers
230 views

Can this theory on the evolution of human appearance be flawed?

This is what a friend of mine said: When there's human offspring, it will look a rough 'medium' between the two parents, with it sharing features from the two. well if the offspring of one set ...
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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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2answers
164 views

Evolutionary history: did any organs start out as autonomous organisms?

I've read that the cell nucleus was once an autonomous organism that was "enslaved" by the larger cell at the time of the Eukaryotic Revolution. Are there any organs in the human body that we know of ...
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180 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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91 views

Reproductive isolation causing evolution

My course book says about reproductive isolation that it does not allow the interbreeding among the individuals of different species. It also says that it is a cause of evolution. How is this cause ...
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3answers
166 views

Are domesticated animals really “more intelligent,” or is that a myth/misunderstanding?

Often do I hear people speaking of how the domestic house cats are more friendly, less ferocious, less savage-like, and smarter and/or than their distinct but equivalent feline-species friends, like ...
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1answer
105 views

Why can't we propose a solid theory regarding origin of life?

What information is greatly lacking which does not allow us to propose a solid theory for origin of life ?
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118 views

Evolutionary chronology - if any, which species have evolved in the last 100 years

I heared somewhere, I cannot remember where, that there has not been an evolution observed in our lifetime. In life science class, right at the start, we was doing the usual MRSGREN (how to tell if ...
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1answer
72 views

Do species which have a closer common ancestor to humans tend to be more intelligent?

Q: Do species which have a closer common ancestor to humans tend to be more intelligent? Our closest living relative, the chimpanzee, seems to be regarded as intelligent: Chimpanzees make ...
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3answers
2k views

Why do our eyes close when we sleep?

Why do our eyes close when we sleep? Is it to relax our eye muscles? How can it be explained from an evolutionary point of view?
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1answer
237 views

Birds and Dinosaurs

This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are ...
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2answers
130 views

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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2answers
151 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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1answer
133 views

Did spiders respond to light for building webs before artificial light was invented?

I have noticed that during summer, beautiful spider colonies grow wherever a strong light is: I'm wonder whether spiders evolved to seek naturally lighted areas where they build nests (before ...
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2answers
122 views

Which was the last significant event in human evolution? What's next?

At 10.000 BC (12 ka), we became the last of the Homo species on Earth. In evolutionary terms this is a very little time range to something happen, but I'm wondering anyway, in this meantime which are ...
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1answer
2k views

Why do different humans look different?

Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trail across the animal kingdom: one individual of ...
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1answer
154 views

What's the Evolutionary Purpose of Religion? [closed]

I would imagine the answer to this question would be that religion tends to cause greater compliance of individuals within society, so it is pro-society. Plus these religions tend to incorporate some ...
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2answers
89 views

What does to “evolve” exactly mean? [closed]

In this article, the author says: Evolution isn’t “leading up” to anything, it just drunkenly limps along using the same set of tricks in slightly different orders. On other occasions, however, ...
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1answer
81 views

Evolution, What would the first plants have been like?

I am curious what the first plants are thought to have been like, what they may have evolved from, and how much earlier (or later) than animals they are thought to have moved to land, if they even ...
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2answers
97 views

Effect on fitness of mutations

What is the distribution/probability density function (PDF) of impacts on fitness of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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2answers
71 views

Aren't current explanations for the evolution of human cooperation a little too reductionist?

Lately, I've become a believer in the limits of reductionist explanations especially in areas like complex systems and biology. So, without wasting any more time, I'll get to my question.. Whenever ...
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1answer
113 views

Can we say that microevolution and macroevolution is fundamentally the same thing over different time scales?

This Wikipedia article states: Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast ...
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180 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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246 views

Does evolution destroy functional sequences much faster than it creates them in any large-genome animal with low reproductive rates?

Recently I have found myself in a discussion with a guy that isn't a creationist, but denies evolution. He cites several studies that show problems like this one, but I do not have the knowledge to ...
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1answer
1k views

What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
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1answer
49 views

Can life forms exist from simple structures not made of the four bases? [closed]

I understand that all life forms on the planet are made from adenine, gauatine, cytosine and thymine, which chemically joined together to form RNA or DNA (correct me if I'm wrong). This goes on to ...
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1answer
58 views

Which came first in hominid evolution: language or bipedalism? [closed]

I suspect both language-use and upright-posture have anatomical consequences. So does the fossil record show which came first? NOTE: To the folks who marked this question "homework": This is ...
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2answers
135 views

How can natural selection occur at species level whilst not occuring at the individual level?

The chapter by Douglas Futuyma in 'Evolution' (Losos et al 2013, Princeton) states that natural selection can occur at the species level. Futuyma states that if natural selection occurs at the species ...
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1answer
32 views

Does documentation exist that shows the evolutionary connection between common horses and the okapi?

I'm trying to put together some documentation on the relation between the common (modern) horse and the okapi. I've found a tree that shows that connection but it has no references. I'm hoping that ...
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1answer
87 views

Has any creature ever devolved to be cold blooded? [closed]

Is this even possible? Because I have a non-scientific gut feeling that it is irreversible. Whales and dolphins are evolved from land mammals, and they've remained warm blooded while it doesn't give ...
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1answer
80 views

Why are hens so different from other birds? [closed]

Hens lay many eggs during their lifetime (at least, I don't know of one which can lay more eggs) and they can't fly. Compared to other domestic animals it seems to me they are the least capable of ...
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1answer
100 views

What is the evolutionary reason behind human preference for salty foods?

It's been established that food palatability is related to it's caloric density. This hypothesis is used to explain why humans are partial to sugar and fat. But it is also said that humans are partial ...
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1answer
169 views

definition of tempo and mode in evolution

I am reading Punctuated Equilibria: The Tempo and Mode of Evolution Reconsidered, which mentions the "tempo" and "mode" of evolution. I'm not familiar with the related literature and when I google the ...
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1answer
38 views

Dominance/recessivity of new mutations

What is the distribution/probability density function (PDF) of recessivity/dominance of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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1answer
126 views

Is Natural Selection like a Copy Editor?

I am stuck on a Homework Question. It says: Evaluate the following statement: “Natural selection works like a copy editor; it works only with what is already present in a population.” (Note: ...
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1answer
980 views

Evolution- Variations, adaptations and selective advantages

I am trying to understand Variations, adaptations and selective advantages and how they are all related. Feel free to add or correct me if I'm wrong- Variations are structural, functional, or ...
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1answer
1k 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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1answer
222 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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1answer
330 views

Does a fully-resolved phylogenetic tree have to be dichotomous?

I read that wherever there is polytomy there is an unresolved pattern of divergence. I don't understand why this is so. When divergence takes place, is it necessary that there will be division into ...
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2answers
218 views

Has medical progress stopped human evolution? [duplicate]

We can cure many diseases nowadays, and thus the natural selection is very limited. Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he ...
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1answer
131 views

Lineage selection in plasmid evolution

I've been reading through Paulsson (2002) and I am not sure what he means by "lineage selection" in the second to last section. The paper deals with plasmid replication, and mostly concentrates on the ...
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2answers
151 views

Plants without bacteria? is it theoretically possible?

I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But ...
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1answer
28 views

What factors, other than its homochirality, make our “brand” of biology unique? [closed]

If humans were to discover organisms on another planet, it is supposed that (unless both we and they were seeded by the same source) we would have nothing to fear from alien pathogens, as they would ...
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1answer
70 views

What is the relationship between radiation and evolution?

There is always a certain amount of background radiation present, for example due to ionizing radiation from the sun and other stars. Also certain materials like granite may emit relatively large ...
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1answer
36 views

What is different between the pigment of giraffes and the pigment of flowers?

I saw this video created by Derek Muller and he says there that it is very unusual to evolutionary develop the colour of the skin without the pigment. That sounds reasonable but if so, what nutrients ...