Polygenic Inheritance
Have you ever wondered what makes you unique? The reason you are unique is because of genetic variation. Genetic variation is what makes humans all look different than each other such as hair color, eye color and skin color . Variation in the same species is based on genetic and environmental factors. Species that are the same have very similar genes but are not exact. This has to do with sexual reproduction traits of parents and offspring, parents give half of each chromosome pair. It is uncommon for there to be variation that genes carry resulting in a mutation. Genes control the traits in an organism but the environment and DNA does change things like appearance, behavior and having an offspring.
Human height
With more genetic variation, there are more “options” to be selected for. A lot of variation makes it so a species can become best adapted for an environment.
Evolution is the process by which organisms develop unique derived traits. Evolved traits that decrease an organism’s survival rate are selected against in a population. Traits that increase an organism’s survival rate, on the other hand, are often selected for, meaning that those traits will appear more frequently in the genetic codes of members in a population. This process of selection can take several forms, one of them called sexual selection. Sexual selection occurs when one member of a particular species selects a mate with more favorable traits than other members of their species. An example of sexual selection would be the evolution of “hairlessness” in modern humans. Modern humans do not have a single coat of undiversified hair, unlike
People sometimes wonder how organisms get so different from their ancestors. The answer is through their genes. Organisms over generations are always adapting to the environment. They are becoming better fit for survival to reproduce and live. The rock pocket mice were tested under different gene traits and environmental conditions to see what rock pocket mice would survive and reproduce more offspring. The different environments the mice were measured under are the ice age or desert and the different alleles that were tested were color, thickness of fur, and strength of jaw. Brown is dominant to white, normal fur is dominant to thick, and normal strength is dominant to strong. Of course through
The study of heredity is what is referred to as genetics. Genetic diversity is therefore described as any variation in the genes, chromosomes, nucleotides or sometime change in the whole genomes of an organism. Though genome is not well branded term for many, it is the entire balance of DNA within the cell or organelles of the organism. When one talks of genetic diversity in its most elementary level, it is represented by differentiation in the sequence of nucleotides that form the DNA within the cell of an organism.
Mutation is a change in the organism's DNA. This change causes the gene pool too to change in an individual. It is rare, but it can have a cumulative effect over time. Mutations are uncommon but the source to all real new changes, but overall the new alleles rely on natural selection and genetic drift. If Drew Fish had a mutation that gave it legs and it began to mate with a member of the population it will be introducing a new gene to the population gene pool. Natural selection can cause change because in reproduction in which preferred Drew Fish mate can cause an increase in numbers of homozygous individuals in the population. Populations in a species consist of different genetic makeups, some of them are more successful at leaving offspring than
People from various parts of the world have different features that can be used to identify where they originate. The question of whether or not human races truly exist is now a prevalent one in the scientific community. Some scientists believe that race is biologically meaningless while others believe that race can be used to determine medical treatment for a person (Jorde & Wooding, 2004). Although there are genes that determine the different physical characteristics of people their genetic variation is mainly due their geographic location. There is some biological basis for the phenotypic differences in humans, but the way we define and understand these differences are flawed. There is no individual trait or gene that separates members of one race from all the members of another race (Brace & Gill, 2000).
Dr. Wilmut’s cloning of Dolly the sheep from an adult ewe has been sharply challenged by Dr. Norton D. Zinder, a microbiologist at Rockefeller University. Zinder believes that it is possible, however there is simply not enough evidence to prove it. It was noted that the cloning of the sheep was only successful a mere 1 out of 400 times, which, in science, is not a successful result according to Zinder. Dr. Wilmut also failed to mention that the sheep from which Dolly was cloned had died many years prior to the cloning which is a huge red flag in the credibility of the success of this experiment. I definitely believe that this cloning experiment was unsuccessful. I am very interested in cloning, and find it very awesome that you can take the genes of one mammal and create an exact replica.
They carry a different genetic code from their mother that determines their shoe size, fingerprints, hair and eye color, and several other features.
Evolution has always been an area of great fascination for me. Since the beginning of my journey as a Life Sciences student, evolution has always been my favourite section alongside the human anatomy. Learning more and more about the human anatomy, I leant that all humans are the same on the inside, but we’re all different on the outside. In grade 10 we learnt that all humans originated from one place on Earth but in grade 12, we learnt that humans have the same genotype (all the genes an organism carries in its chromosomes) but since all of this is true, why is it that we all have various phenotypes( appearance of an organism) ? This led me to wonder why is it that according to Darwin. C, (1959) “Out of Africa theory” we all come from the same place, and are built the same but we don’t all look like those who still live in the origin of mankind? Why doesn’t everyone look like a true African man or woman? Why aren’t we all black?
The DNA code, that forms our genes, was the missing key for Darwin to understand how things evolved. DNA does not stay the same, it can be changed by mutations. Mutations are needed to generate variations. Without the mutations things would stay the same generation after generation. Pieces of DNA called a switch can turn certain genes on or off. Genetic Switches helps to create mutations which are sometimes responsible for an entire new species spawning from another. This is how a snake can evolve from a four legged animal, and how a whale 's front flippers has bones inside that resembles
Researching my family genogram helped me explore the genealogy of my family and the traditions and medical and mental health patterns of behaviors that exist in my family.
Now, let's say we were examining an experiment performed on a set of identical twins. Twins are born with the same genetic makeup, which has been shaped by this world.
more than half the variation was found to be due to heredity. Among these traits were
The phenomena of the presence or existence of different morphs or phenotypes in a particular species belonging to a particular population at the same time and place is called polymorphism. The morphs should be present in frequencies high enough to be noticed readily. Polymorphism is usually the result of mutation.
Every individual surviving on this Earth is incredibly unique in every respect. Man though have descended from a common ancestor had gradually accumulated over a long period of time different changes. These changes are a gradual process leading to change in gene frequencies of a population and in course of time results in their different genetic make up. One individual differs from other not only in terms of physical appearance like height, weight, skin colour, nose pattern, facial appearance etc but also has different eating habits, behaviour and culture. The physical variation observed among human populations surviving in different geographical regions of the world or even those of the same region is a clear evidence of ever going human evolution.