Answer:
Natural selection is generally limited to modifying structures that were present in previous generations and in previous species
Explanation:
The basic idea of biological evolution is that populations and species of organisms change over time. Today, when we think of evolution, we are likely to link this idea with one specific person: the British naturalist Charles Darwin.
In the 1850s, Darwin wrote an influential and controversial book called On the Origin of Species. In it, he proposed that species evolve (or, as he put it, undergo "descent with modification"), and that all living things can trace their descent to a common ancestor.
Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population violates the Hardy-Weinberg assumptions, and evolution occurs. The Hardy-Weinberg Theorem thus provides a null model for the study of evolution, and the focus of population genetics is to understand the consequences of violating these assumptions.
New gene variants (i.e., alleles) are produced by random mutation, and over the course of many generations, natural selection may favor advantageous variants, causing them to become more common in the population.
<span>If cells are unregulated they can over proliferate and cause things like cancer. Abnormal cellular growth causes tumors and improper resource distribution. Unregulated cellular processes use up nutrition not readily available and can cause harm to cells around the tumor.</span>
BTX or batrachotoxin is a type of steroidal alkaloid which was first derived from the skin of Dendrobatidae or poison dart frogs. This neurotoxin prevents the muscle and nerve cells from transmitting electrical signals. The toxin permanently blocks electrical signal transmission from the nerves to the muscle by binding and inactivating the sodium channels.
An ecological pyramid is a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem. Biomass pyramids show how much biomass is present in the organisms at each trophic level, while productivity pyramids show the procreation or turnover in biomass.
