Darwin’s Theory and Evolution: Key Concepts Explained
Darwin’s Theory and Evolution: Key Concepts
1) The Importance of Darwin’s Theory: Darwin’s major development theories aimed to prove that life emerged, deviating from lower to higher forms. With the passage of time, this evolutionary process became more complex, causing better-adapted individuals to exist. Animals and plant species inhabiting the Earth are subject to change, and it is through these changes that new forms of development originate.
2) Evolution: The process of continuous change over time that all living things undergo.
3) Types of Changes:
a) Divergent: Natural selection occurs when pressure is exerted, causing some populations to become isolated from the rest of their species.
b) Convergent: Occurs when organisms occupy similar environments and, being genetically similar, enter them and even have a distant kinship.
4) Selection: An evolutionary mechanism defined as the differential reproduction of genotypes within a biological population. In its initial form, the theory of evolution by natural selection is the great achievement of Charles Darwin.
5) The Theory on the Origin of Living Things:
a) Fixist Theory: The various living species that exist arose from a process of creation and have remained unaltered, without experiencing any change throughout the history of the land. Also based on textual interpretation of the Bible. It is supposed that some living things died out due to the catastrophe described in the Bible.
b) Lamarck’s Evolutionary Theory: Openly contradicted previous theories and suggested that the species today are the result of a long process of change that all living things have experienced. This theory caused great controversy and was eventually rejected by the scientists of the time. New features are passed to descendants, i.e., there is an inheritance of characters acquired during life.
c) Darwin’s Evolutionary Theory: In the populations of a species, not all individuals are identical; there is variability. When environmental conditions become unfavorable for most individuals, those with a difference that allows them to overcome this difficulty have an advantage over the rest. These inherit the advantages that their parents represented.
d) Neo-Darwinian Theory: Hugo de Vries discovered Mendel’s work on the inheritance of characters. The transmission of characters to the descendants carries the information of the characteristics of each individual.
e) Synthetic Theory of Evolution: In all populations of living beings, mutations occur randomly, causing variability. Having variability, nature selects the best-adapted individuals, i.e., those who have some sort of advantage in unfavorable conditions. The process is repeated in future generations.
6) Evidence of Evolution:
a) Fossil Record: Remnants of beings who lived in ancient times, preserved thanks to having undergone a process of fossilization.
b) Adaptation: The ability of an individual to live and develop in a given environment.
c) Species: A group of individuals similar in nature that reproduce, including fertile descendants.
d) Mimicry: Occurs when an organism acquires coloring or shapes similar to those in the environment where it is, due to a mechanism that allows some reaction in extreme occasions.
e) Speciation: Occurs as a result of the geographical separation of a population of organisms.
7) Types of Adaptation:
a) Structural: When an organism develops structures that allow it to survive. For example, many insects mimic the forms of the plants where they live to protect themselves from predators.
b) Physiological: Some organisms have physiological mechanisms that allow them to adapt to the environment.
c) Behavioral: When some organisms acquire a different behavior than normal to try to confuse predators and achieve their survival.
8) Types of Mimicry:
a) Topomorphic: When the animal takes the color and resemblance of the land where it is, such as the lizard.
b) Phytomorphic: When the animal takes the color and resemblance to the plant where it is, for example, the iguana, chameleon, and some butterflies.
c) Zoomorphic: When the animal takes the form of another animal to protect itself, for example: