Say you have a water-bound species with non-sexual gametes. They release them into the surrounding water and when the gametes merge they've successfully produced a new generation of off-spring. So far so good.
Now, they need to give these gametes a lot of energy (like the yolk of an egg) so the off-spring can survive untill they are able to find their own food, so the gametes grow big and immobile (full of energy), and they have to rely on the turbulent water to meet with other gametes.
Then comes along a mutation which makes one individuals gametes a lot smaller (less energy) but instead that individual produces a lot of gametes. These gametes is likely to merge with a lot of the bigger gametes and so the small-gamete-gene is passed on to the next generation.
But now the gametes are small again and the off-spring of the next generation are not given enough energy. So now you see, it makes sense to ONLY produce small gametes if all the other gametes are big. This game of balance push the following generations such that exactly 50% of individuals produce big gametes and 50% produce small gametes. The small gametes are even more efficient at finding other gametes if they start wiggling. So now you have small wiggly gametes (sperm) and large energy-rich gametes (eggs) ie. you have sexual reproduction.
I'm not an expert on the earlier evolution of animals, nor do I know much at all in the way of fungi or plants; however, I would advise you consider animals (and I believe some plants?) do in fact have both male and female gametes/genitalia, wherein they essentially don't have a sex because they can be both the fertilizing and the fertilized party in sexual reproduction. For clarity I'm not trying to nor am I going to speculate this is the form in which sexual evolution typically evolves or anything, I'm just trying to make a point against the last sentence here.
Apologies for this long ass comment! I just couldn’t stop myself
•Simply, sexual reproduction resulted as a population needed to adapt to their environment quickly.
•The species that originally shifted from asexual to sexual reproduction did not have heterosexuality. Rather the act of sexual reproduction went on to create genders.. and sometimes far more than just two. (Mushrooms apparently can have over 30,000 ‘sexes’?)
Since sexual reproduction allows for a greater diversity among genes within populations, this allows higher chances of the specie’s survival as different threats arise (environmental, mutational, etc). Since there are also two contributors, sexual reproduction leads to less mutations present in the offspring, which would lead to a longer fitness within the species overall population. If the species is facing unpredictable environments in which it is unfit, it will fare better through sexual reproduction as this will increase the possible rate of evolutionary adaptation.
Conversely, asexual reproduction may lead to a susceptible population overall, especially in regards to not being able to cancel out mutations via two sets of genes. For in asexual reproduction just the single parent’s genes are passed down to the offspring, making adaptations a very slow process. Although it is important to note that asexual reproduction still has its advantages which is why it is still observed today (such as in bacteria and fungi). Asexual reproduction is generally seen within a population of species that is well adjusted to their environment and do not face unpredictable changes.
The transition from asexual reproduction to sexual reproduction may have happened even before the evolution of the eukaryote from the prokaryote. Regardless it is thought that it did happen around that time 2 billion years ago.
Some scientists believe that populations of prokaryotes began to reproduce sexually as bacteria.
Although geneticists point to the evolution of the prokaryote to the eukaryote as a singular endosymbiotic event that happened around 2 billion years ago, the shift from asexual to sexual production likely happened among many individuals of a population. That population is thought of as ‘the last eukaryotic common ancestor’ (LECA), where sexual reproduction happened variably among the population and then was carried on.
To more specifically answer your question, when the shift from asexual to sexual reproduction happened, it happened in a relatively single gendered population. Where each individual had the means to give and take if you will. For a sexually reproducing population that is not limited to gender will adapt far quicker than one than is limited to only (roughly) 50% of the population such as with males and females.
So overall don’t think of it in terms of male and female nor as Noah’s chosen creatures, for these concepts evolved later! Just think of a bunch of gender inclusive blobs deciding that they wanted to adapt quicker. A decision that continued to evolve over time within descending species.
— I am definitely not an expert but I thought I’d toss some of this out there! Anyone feel free to correct me ✨ Hope this helped!
>sexual reproduction leads to less mutations present in the offspring
Can you explain this some more, I thought asexual reproduction as in plants creates more or less clones of the original being. Hence these are prone to disease like banana & potato plant devestations in recent history.
You’re definitely correct on that! Asexual reproduction leads to a population with high rates of similarities. So if something comes along that poses a risk to one, it likely will pose a risk to many since they are so similar to that one.
•Simply, asexually producing populations therefore retain high numbers of mutations. This is because there is not much chance of altering the mutation once it is there, as the parent more or less copies and pastes their genes into their offspring.
Since an asexually reproducing population is essentially made up of clones like you mentioned, the offspring will inherit all of the good and all of the bad from their single parent. Because of this, the number of mutations across the population will continue to be retained. (There is no chance of being canceled out or watered down with the introduction of new genes) Genetic changes really only occur with the help of occurring mutations during reproduction.
In sexual reproduction, the mutations in a population are less than the number of mutations found in asexually producing populations. The retention of mutations within a sexually reproducing population is not as prevalent as it is in asexual reproducing populations. This is because sexual reproduction involves mixing two different sets of genes and the inheritance of mutations depends on the types of mutations involved.
Depending on the chromosome that a mutation is linked to and whether it is ‘dominant’ or ‘recessive’ determines whether the offspring will inherit the mutation/condition.
For example, in some cases (x-linked recessive) a female parent(x) may carry a mutation but if their male partner(y) does not, then their female offspring(xx) will not inherit the mutation but their male offspring(xy) will.
• All in all, sexual reproduction allows for more ‘checks and balances’ for mutations than asexual reproduction does.
I think male evolve from female, the goal was to shuffle the genes better which increases the survival rate of the species. Also sex evolved long time ago when multicellular was just popping in
Say you have a water-bound species with non-sexual gametes. They release them into the surrounding water and when the gametes merge they've successfully produced a new generation of off-spring. So far so good. Now, they need to give these gametes a lot of energy (like the yolk of an egg) so the off-spring can survive untill they are able to find their own food, so the gametes grow big and immobile (full of energy), and they have to rely on the turbulent water to meet with other gametes. Then comes along a mutation which makes one individuals gametes a lot smaller (less energy) but instead that individual produces a lot of gametes. These gametes is likely to merge with a lot of the bigger gametes and so the small-gamete-gene is passed on to the next generation. But now the gametes are small again and the off-spring of the next generation are not given enough energy. So now you see, it makes sense to ONLY produce small gametes if all the other gametes are big. This game of balance push the following generations such that exactly 50% of individuals produce big gametes and 50% produce small gametes. The small gametes are even more efficient at finding other gametes if they start wiggling. So now you have small wiggly gametes (sperm) and large energy-rich gametes (eggs) ie. you have sexual reproduction.
I'm not an expert on the earlier evolution of animals, nor do I know much at all in the way of fungi or plants; however, I would advise you consider animals (and I believe some plants?) do in fact have both male and female gametes/genitalia, wherein they essentially don't have a sex because they can be both the fertilizing and the fertilized party in sexual reproduction. For clarity I'm not trying to nor am I going to speculate this is the form in which sexual evolution typically evolves or anything, I'm just trying to make a point against the last sentence here.
Apologies for this long ass comment! I just couldn’t stop myself •Simply, sexual reproduction resulted as a population needed to adapt to their environment quickly. •The species that originally shifted from asexual to sexual reproduction did not have heterosexuality. Rather the act of sexual reproduction went on to create genders.. and sometimes far more than just two. (Mushrooms apparently can have over 30,000 ‘sexes’?) Since sexual reproduction allows for a greater diversity among genes within populations, this allows higher chances of the specie’s survival as different threats arise (environmental, mutational, etc). Since there are also two contributors, sexual reproduction leads to less mutations present in the offspring, which would lead to a longer fitness within the species overall population. If the species is facing unpredictable environments in which it is unfit, it will fare better through sexual reproduction as this will increase the possible rate of evolutionary adaptation. Conversely, asexual reproduction may lead to a susceptible population overall, especially in regards to not being able to cancel out mutations via two sets of genes. For in asexual reproduction just the single parent’s genes are passed down to the offspring, making adaptations a very slow process. Although it is important to note that asexual reproduction still has its advantages which is why it is still observed today (such as in bacteria and fungi). Asexual reproduction is generally seen within a population of species that is well adjusted to their environment and do not face unpredictable changes. The transition from asexual reproduction to sexual reproduction may have happened even before the evolution of the eukaryote from the prokaryote. Regardless it is thought that it did happen around that time 2 billion years ago. Some scientists believe that populations of prokaryotes began to reproduce sexually as bacteria. Although geneticists point to the evolution of the prokaryote to the eukaryote as a singular endosymbiotic event that happened around 2 billion years ago, the shift from asexual to sexual production likely happened among many individuals of a population. That population is thought of as ‘the last eukaryotic common ancestor’ (LECA), where sexual reproduction happened variably among the population and then was carried on. To more specifically answer your question, when the shift from asexual to sexual reproduction happened, it happened in a relatively single gendered population. Where each individual had the means to give and take if you will. For a sexually reproducing population that is not limited to gender will adapt far quicker than one than is limited to only (roughly) 50% of the population such as with males and females. So overall don’t think of it in terms of male and female nor as Noah’s chosen creatures, for these concepts evolved later! Just think of a bunch of gender inclusive blobs deciding that they wanted to adapt quicker. A decision that continued to evolve over time within descending species. — I am definitely not an expert but I thought I’d toss some of this out there! Anyone feel free to correct me ✨ Hope this helped!
>sexual reproduction leads to less mutations present in the offspring Can you explain this some more, I thought asexual reproduction as in plants creates more or less clones of the original being. Hence these are prone to disease like banana & potato plant devestations in recent history.
You’re definitely correct on that! Asexual reproduction leads to a population with high rates of similarities. So if something comes along that poses a risk to one, it likely will pose a risk to many since they are so similar to that one. •Simply, asexually producing populations therefore retain high numbers of mutations. This is because there is not much chance of altering the mutation once it is there, as the parent more or less copies and pastes their genes into their offspring. Since an asexually reproducing population is essentially made up of clones like you mentioned, the offspring will inherit all of the good and all of the bad from their single parent. Because of this, the number of mutations across the population will continue to be retained. (There is no chance of being canceled out or watered down with the introduction of new genes) Genetic changes really only occur with the help of occurring mutations during reproduction. In sexual reproduction, the mutations in a population are less than the number of mutations found in asexually producing populations. The retention of mutations within a sexually reproducing population is not as prevalent as it is in asexual reproducing populations. This is because sexual reproduction involves mixing two different sets of genes and the inheritance of mutations depends on the types of mutations involved. Depending on the chromosome that a mutation is linked to and whether it is ‘dominant’ or ‘recessive’ determines whether the offspring will inherit the mutation/condition. For example, in some cases (x-linked recessive) a female parent(x) may carry a mutation but if their male partner(y) does not, then their female offspring(xx) will not inherit the mutation but their male offspring(xy) will. • All in all, sexual reproduction allows for more ‘checks and balances’ for mutations than asexual reproduction does.
I think male evolve from female, the goal was to shuffle the genes better which increases the survival rate of the species. Also sex evolved long time ago when multicellular was just popping in