Humans are a part of the second group. Did you know that humans used to be quadrupeds, meaning they walked on all fours? Then they became bipeds, meaning they walked on their two back legs. Their brain size also got larger as time passed. This is how modern humans evolved.
Wow, that’s so interesting! So we are related to monkeys but didn’t evolve from them! What else can you tell me about evolution?
Ok! Let me tell the different ways that evolution occurs. There are 4 main mechanisms.
The first is natural selection. The second is mutations. A mutation is when there is a change in the DNA sequence of one gene, giving rise to a new allele in the population that is either beneficial or detrimental for the species.
Genetic drift, on the other hand, is when genes in a population disappear due to chance, such as sudden deaths or not being able to reproduce.
Then we have gene flow and genetic drift. Gene flow is known as the transfer of alleles from one population to another due to the migration of individuals in and out of a population.
Wow! There is much going on! But Dad, why have some species relocated but some stayed in the same geographic location?
That’s a good question that can be answered by the 2 modes of speciation.
The second is sympatric speciation when groups of species evolve into different species but are in the same geographical location.
The first mode of speciation is allopatric. Allopatric speciation is when groups of species evolve into different species and adapt to different geographic locations.