1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
amm1812
3 years ago
14

Explain how the following factors support the mechanisms of evolution: a. b. Gene Flow

Biology
1 answer:
vladimir1956 [14]3 years ago
7 0
1.- Natural Selection

Natural Selection leads to an evolutionary change when some individuals with certain traits in a population have a higher survival and reproductive rate than others and pass on these inheritable genetic features to their offspring. Evolution acts through natural selection whereby reproductive and genetic qualities that prove advantageous to survival prevail into future generations. The cumulative effects of natural selection process have giving rise to populations that have evolved to succeed in specific environments. Natural selection operates by differential reproductive success (fitness) of individuals.

The Darwin’s Finches diagramillustrates the way the finch has adapted to take advantage of feeding in different ecological niches:

2.- Genetic Drift

Random Drift consists of random fluctuations in the frequency of appearance of a gene, usually, in a small population. The process may cause gene variants to disappear completely, thereby reducing genetic variability. In contrast to natural selection, environmental or adaptive pressures do not drive changes due to genetic drift. The effect of genetic drift is larger in small populations and smaller in large populations.

Genetic drift is a stochastic process, a random event that happens by chance in nature that influences or changes allele frequency within a population as a result of sampling error from generation to generation. It may happen that some alleles are completely lost within a generation due to genetic drift, even if they are beneficial traits that conduct to evolutionary and reproductive success. Allele is defined as any one of two or more genes that may occur alternatively at a given site (locus) on a chromosome. Alleles are responsible for variations in a trait.

The population bottleneck and a founder effect are two examples of random drift that can have significant effects in small populations. Genetic drift works on all mutations and can eventually contribute to the creation of a new species by means of the accumulation of non-adaptive mutations that can facilitate population subdivision.

In population genetics, Gene Flow(also known as gene migration) refers to the transfer of genes from the gene pool of one population to another. Gene flow may change the frequency and/or the range of alleles in the populations due to the migration of individuals or gametes that can reproduce in a different population. The introduction of new alleles increases variability within a population and allows for new combinations of traits. Horizontal gene transfer (HGT) also known as lateral gene transfer (LGT), is a process in which an organism (recipient) acquires genetic material from another one (donor) by asexual means. It is already known that HGT has played a major role in the evolution of many organisms like bacteria. In plant populations, the great majority of cases linked to this mechanism have to do with the movement of DNA between mitochondrial genomes. Horizontal gene transfer is a widespread phenomenon in prokaryotes, but the prevalence and implications of this mechanism in the evolution of multicellular eukaryotes is still unclear. Nevertheless, many investigations on HGT in plants have been carried out during the last years trying to reveal the underlying patterns, magnitude and importance of this mechanism in plant populations as well as its influence on agriculture and the ecosystem.

Plant populations can experience gene flow by spreading their pollen long distances away to other populations by means of wind or through birds or insects (bees, for example) and once there, this pollen is able to fertilize the plants where it ended up. Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes (comparable to sperm cells). Of course, pollination does not always lead to fertilization.

Maintained gene flow also acts against speciation by recombining the gene pools of different populations and in such a way, repairing the developing differences in genetic variation.Thus, gene flow has the effect of minimizing the genetic differences between populations.

Human migrations have occurred throughout the history of mankind and are defined as the movement of people from one place to another. However, in a genetic context, this movement needs to be associated with the introduction of new alleles into a population through successful mating of individuals from different populations.






You might be interested in
Fires are important to savanna ecosystems but not grasslands
Akimi4 [234]
The correct answer for the question that is being presented above is this one: "FALSE." <span>Fires are important to savanna ecosystems but not grasslands. </span><span>Well this would be false, considering that savanna are the same as grasslands. More or less they are the same.</span>
7 0
3 years ago
Read 2 more answers
What is hepatitis c​
Mrrafil [7]

Answer:

Virus

Explanation:

Hepatitis C virus, a member of the Hepacivirus C species, is a small, enveloped, positive-sense single-stranded RNA virus of the family Flaviviridae. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer and lymphomas in humans

5 0
3 years ago
Read 2 more answers
Which method of food production is sustainable?
yarga [219]

Answer:

Improving food storage facilities

4 0
3 years ago
Read 2 more answers
Which macromolecule forms a double layer as the primary structure of cell membranes?
OlgaM077 [116]
Answer;
Phospholipid.

Phospholipid forms a double layer as the primary structure of cell membranes.

Explanation; 
Cell membranes contains of lipids (phospholipids and cholesterol), proteins and carbohydrates groups that are attached to some of the lipids and proteins. 
Phospholipids are composed of a polar head and non-polar (hydrophobic) tail. They line up such that the heads and the tail groups are side by side to form a single layer due to the interactions between the head groups and the tail groups. Two of these layers line up with the hydrophobic tail groups facing each other to prevent the hydrophobic groups away from the polar head groups of other phospholipids and from the water in the surrounding environment. 
6 0
3 years ago
Read 2 more answers
Granite is a coarse or medium-grained rock that is rich in quartz and feldspar. It is formed when bodies of magma cool and harde
drek231 [11]

Answer:

Igneous

Explanation:

3 0
3 years ago
Other questions:
  • Which factor is a major cause of the changes that occur during puberty?
    12·1 answer
  • Darwin believed in the idea that evolution happened slowly over a long period of time called what
    12·1 answer
  • The components of the plasma membrane that can transport solutes through the plasma membrane are __________.
    6·1 answer
  • Which is true about one strand of DNA?
    7·2 answers
  • A problem caused by the overuse of fertilizer that results in algal blooms like this is known as
    10·2 answers
  • The number of sperm cells that form from a primary spermatocyte is, whereas the number of functional egg cells that form from a
    11·1 answer
  • Please help will mark brainliest answer.Which of the organisms in this food web obtains its energy from BOTH producers and consu
    11·1 answer
  • Which of the following statements below are TRUE about Keystone Species? Pick all that are correct
    14·1 answer
  • Does anybody here know how to edit two pictures into one?
    8·1 answer
  • The fruit fly, drosophila melanogaster (d. melanogaster) is an excellent model for studying fundamentals of development because?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!