VCE Biology Question Thread

[katiesaliba]

Which hominin species was the first to leave Africa?  Homo erectus? Also, Homo heidelbergensis is the intermediate predecessor to both neanderthals and modern humans, right?

I've come across a NEAP question that required us to know the rough dates of each major hominin species. Is this unnecessary knowledge?

Also, for blood clotting, do we only need to know that platelets agglutinate due to clotting factors?

What would be the selective advantage for:
-the location of the ear bones moving forward
-larger vertebrae (more neural networks?)

Actually, while I'm on that, did the nervous system evolve to become more complex, therefore increasing motor aptitude, memory retention and pain sensitivity? Would increased neural networks result in greater intelligence?

Woah. Sorry about that word vomit of questions  Thanks, guys! 

[vox nihili]

Which hominin species was the first to leave Africa?  Homo erectus? Also, Homo heidelbergensis is the intermediate predecessor to both neanderthals and modern humans, right?

This is relatively contentious, because there's a bit of debate surrounding which one did leave first. The most popular answer is Homo erectus. It's important to realise though that, though Homo erectus did leave first, those that left did not give rise to Homo sapiens. Rather, Homo sapiens arose in Africa and then followed Homo erectus out of Africa.

[shivaji]

For this question, the answer is B, but I thought the answer was A... because isn't gene pool the sum total of all alleles, and NOT allele frequencies, so there necessarily doesn't mean great genetic diversity because all alleles could essentially be the same?

If the gene pool of a population is large, this
indicates that:
A there are a large number of organisms in the
population.
B there is extensive genetic diversity in the
population.
C the organisms in the population are fi t.
D there is a high chance of extinction.

[RazzMeTazz]

If the robusts are a type of Australopithecus, then why are they sometimes termed 'Paranthropus'?

I'm confused..

Also, how does a shorter and more bowl-shaped pelvis allow for bipedal locomotion?

Thanks!

[althepal]

For this question, the answer is B, but I thought the answer was A... because isn't gene pool the sum total of all alleles, and NOT allele frequencies, so there necessarily doesn't mean great genetic diversity because all alleles could essentially be the same?

If the gene pool of a population is large, this
indicates that:
A there are a large number of organisms in the
population.
B there is extensive genetic diversity in the
population.
C the organisms in the population are fi t.
D there is a high chance of extinction.

I think when we talk about the sum of the alleles we talk about the sum of the different alleles. As in if you had a greater variety of alleles the gene pool would be larger regardless of how many individuals there are in that population.

[kk.08]

Yeah I agree with what althepal said, if you have a larger gene pool chances are that you would have greater genetic diversity due to the greater variation existing in genes as a result of sexual reporoduction, gene flow and what not.

However, a small gene pool would would have a limited sum of alleles/genes and even when gene flow/mutation/sexual reproduction does occur it will not have as  much variation as a large gene pool.

[vox nihili]

For this question, the answer is B, but I thought the answer was A... because isn't gene pool the sum total of all alleles, and NOT allele frequencies, so there necessarily doesn't mean great genetic diversity because all alleles could essentially be the same?

If the gene pool of a population is large, this
indicates that:
A there are a large number of organisms in the
population.
B there is extensive genetic diversity in the
population.
C the organisms in the population are fi t.
D there is a high chance of extinction.

It's actually a combination between A and B that would lead to a large gene pool.

[kk.08]

If the robusts are a type of Australopithecus, then why are they sometimes termed 'Paranthropus'?

I'm confused..

Also, how does a shorter and more bowl-shaped pelvis allow for bipedal locomotion?

Thanks!

So there are two main groups of Australopithecus - Gracile Australopithecus and Robust Australopithecus. The Robust Australopithecus' belong to the genus Paranthropus and are therefore referred to as that. However, they are still a type of Australopithecus.

Also, in terms of the shorter and more bowl-shaped pelvis they allow for bipedal locomotion as it provides more stability and weight support in contrast to the longer pelvis that was designed for quadrupedal motion.

[RazzMeTazz]

So there are two main groups of Australopithecus - Gracile Australopithecus and Robust Australopithecus. The Robust Australopithecus' belong to the genus Paranthropus and are therefore referred to as that. However, they are still a type of Australopithecus.

Also, in terms of the shorter and more bowl-shaped pelvis they allow for bipedal locomotion as it provides more stability and weight support in contrast to the longer pelvis that was designed for quadrupedal motion.

Thankyou!

[RazzMeTazz]

Would it be sufficient to remember the general time in which certain hominins lived, for example: Australopithecus Afarensis lived approximately 3Myr BP and Australopithecus Africanus lived approximately 2Myr BP

Or do we need to know more exact dates?

[vox nihili]

Would it be sufficient to remember the general time in which certain hominins lived, for example: Australopithecus Afarensis lived approximately 3Myr BP and Australopithecus Africanus lived approximately 2Myr BP

Or do we need to know more exact dates?

That's more than enough.

[Reus]

For this question, the answer is B, but I thought the answer was A... because isn't gene pool the sum total of all alleles, and NOT allele frequencies, so there necessarily doesn't mean great genetic diversity because all alleles could essentially be the same?

If the gene pool of a population is large, this
indicates that:
A there are a large number of organisms in the
population.
B there is extensive genetic diversity in the
population.
C the organisms in the population are fi t.
D there is a high chance of extinction.

Think about it. A larger number of organisms will not make the gene pool larger, it will only make the population larger. However larger genetic diversity will increase the size of a gene pool as gene pool's consist of the sum of alleles within a population.

[shivaji]

Think about it. A larger number of organisms will not make the gene pool larger, it will only make the population larger. However larger genetic diversity will increase the size of a gene pool as gene pool's consist of the sum of alleles within a population.

thanks guys, makes sense now!

[shivaji]

when it says what evolutionary process, it is asking for natural or artificial selection only, or is it asking for divergent/convergent evolution

[kk.08]

I don't know, I guess it would depend on the context of the question and what not...but it's something I have difficulty identifying as well, so it'd be great if someone could enlighten us! haha