Video Experimental Relacionado

Updated: Jul 19, 2026

Computer-Generated Animal Model Stimuli
26:43

Computer-Generated Animal Model Stimuli

Published on: July 29, 2007

Origen de los hexápodos: monofilético o parafilético?

Francesco Nardi1, Giacomo Spinsanti, Jeffrey L Boore

  • 1Department of Evolutionary Biology, University of Siena, via Aldo Moro 2, 53100 Siena, Italy. nardifra@unisi.it

Science (New York, N.Y.)
|March 22, 2003
PubMed
Resumen

Collembola, un grupo de artrópodos sin alas, representa un linaje evolutivo distinto y separado de los insectos. Este hallazgo desafía la clasificación tradicional de Hexapoda, impactando nuestra comprensión de la filogenia de los artrópodos y la adaptación terrestre.

Videos de Conceptos Relacionados

The Colonization of Land02:22

The Colonization of Land

Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...
What is Evolutionary History?02:35

What is Evolutionary History?

Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.Phylogenetic trees illustrate the evolutionary relationships among these organisms. Scientists infer organisms’ common ancestry by evaluating shared morphological and genetic characteristics. Together, the fossil...
The Evidence for Evolution02:55

The Evidence for Evolution

Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.
Convergent Evolution01:54

Convergent Evolution

Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...
Eukaryotic Evolution01:24

Eukaryotic Evolution

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Zygotic Development And Stem Cell Formation01:10

Zygotic Development And Stem Cell Formation

The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they...