Scientific Evidence of Evolution and Biodiversity
Scientific Evidence of Evolution
Classic Evidence
- Morphological: The study of comparative anatomy allows us to understand the similarities and differences that the same organ presents in different species.
- Paleontology: Paleontology studies fossils, which allow us to know the ways that life forms existed in the past and study their evolutionary relationship with current life forms.
- Embryological: Embryology studies the early development of organisms. The principle of recapitulation states that the embryonic development of an animal summarizes the evolutionary development of its kind.
- Taxonomic: The system of classification of living things groups organisms with similar characteristics, which is a consequence of a common evolutionary process.
Recent Evidence
Biochemistry and Cellular Biology
- Genetic Code: Establishes the relationship between the sequence of nucleic acids and proteins, with only a few variations (mitochondria, protozoa).
- ATP: The molecule that provides metabolic energy to cells.
- Metabolic and Physiological Processes: The most important processes are common in groups of living things very different from one another (cellular respiration, photosynthesis).
Sequences of Proteins and DNA
The number of differences between the sequences of proteins and DNA is in direct relation to the evolutionary distance between the species being compared.
DNA Hybridization
This is based on the ability of denatured DNA to reassemble hydrogen bonds between the bases of its chains after undergoing a process of denaturation by heat.
Study of Chromosomal Bands
This is the longitudinal study of differences and the characterization of each pair of homologous chromosomes. This way, we can study the karyotype of different species and establish chromosomal homologies.
Immunological Assay or Serological
The introduction of an antigen into an organism results in the production of antibodies, whose intensity depends on the evolutionary relationships between species.
The Result of Evolution: Biodiversity
A species is a set of organisms that have morphological similarities, can reproduce leading to fertile offspring, and present reproductive isolation from other species.
Reproductive isolation is the inability of some organisms to reproduce with others (different populations).
The Process of Speciation
Different factors may promote reproductive isolation between populations of the same species, which can lead to the appearance of two or more different species from one. The most important factor is geographical isolation, which is the separation of populations by physical barriers.
The Classification of Living Things
Taxonomy is responsible for the classification and nomenclature of living things and uses a hierarchical system in which each unit of classification (taxon) is formed by units of the lower category that are evolutionarily related.
Nomenclature: Uses a single word, except in the case of species (binomial system): the name of a species consists of two words in which the first represents the genus.
Taxonomic Categories
- Kingdom: Metazoan
- Phylum: Chordata
- Subphylum: Vertebrates
- Class: Mammals
- Order: Primates
- Family: Hominids
- Genus: Homo
- Species: Homo sapiens
The Five Kingdoms
- Monera: Bacteria and cyanobacteria
- Protoctista: Protozoa and algae
- Fungi: Fungi
- Metaphyta: Plants
- Metazoa: Vertebrates and invertebrates