the endocrine and the nervous systems work together to maintain homeostasis
Red blood cells coagulate wounds; white blood cells defend against bacteria.
u will get breathing problems
There must be genetic variation in the population
The system must not be in hardy-weinberg equilibrium.
resources must be limited in the ecosystem
Platelets
The distribution of alleles changes due to random chance.
or
The allele frequency of a population changes due to a bottleneck effect. <apex>
signals travel from neuron to neuron through neurotranmitters
Population bottlenecks
Reproductive isolation
Niche availability
eyes develop
lips start to form
Vocal cords develop.