Understanding Evolutionary Processes and Species Development

Biogeographical Evidence

Isolated groups evolved in different ways.

Molecular Evidence

The higher the molecular similarities, the closer their evolutionary relationship.

Coevolution

Coevolution is the process by which two species mutually influence each other during their evolution.

Lamarckism

Lamarckism is the theory of inheritance of acquired traits, explaining that animals develop the structures and organs they need in order to adapt to the environment they live in, and these new characteristics are transmitted to offspring.

Darwinism

Darwinism posits that there is competition between the individuals of a species, known as the struggle for existence. Individuals whose characteristics help their survival are favored over those who are poorly adapted (natural selection).

Neo-Darwinism

Neo-Darwinism emphasizes that sexual reproduction creates new combinations of genes, genetic recombination, and mutations.

Neutralism

Neutralism suggests that mutations create genes that are neither beneficial nor harmful, so natural selection does not affect them. Those individuals produce offspring and become isolated, potentially leading to the origin of new species.

Origin of New Species

As a consequence of natural selection, new populations differ from the original ones. New populations do not reproduce with those of the previous population. They accumulate changes due to new mutations and gradually become more distinct, resulting in significant physical differences that prevent reproduction with each other.

Genetic Isolation Mechanisms

• Geographical Barriers: Stop physical contact.
• Sexual Barriers: Anatomical changes prevent mating.
• Physiological Barriers: Incompatibilities in the way gametes work.
• Chromosomal Barriers: Changes in the number or structure of chromosomes.
• Ethological Barriers: New types of behavior result in the rejection of some individuals by others.

Microevolution

Microevolution refers to the appearance of new species.

Macroevolution

Macroevolution involves large groups of organisms.

Phylogeny

Phylogeny is the study of the evolutionary relationships living things have.

Biodiversity

Biodiversity refers to the wide variety of living things that inhabit our planet.

Evolutionary Timeline

• Australopithecus
• Homo habilis (simple tools)
• Homo ergaster (social)
• Homo erectus (use of fire)
• Homo antecessor (Atapuerca)
• Homo neanderthalensis (ritualistic burials)
• Homo sapiens