Video Experimental Relacionado
Updated: Jun 10, 2026

26:43
Computer-Generated Animal Model Stimuli
Published on: July 29, 2007
Escalada evolutiva secundaria entre braquiópodos y enemigos de otras presas
Michal Kowalewski1, Alan P Hoffmeister, Tomasz K Baumiller
1Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. michalk@vt.edu
Resumen
Los ataques depredadores a los antiguos braquiópodos eran raros, a diferencia de los moluscos. Esto sugiere que los braquiópodos eran a menudo víctimas involuntarias de depredadores que atacaban a otras especies.
Área de la Ciencia:
- Paleontología Paleontología.
- Paleoecología Paleoecología.
- Biología evolutiva Biología evolutiva.
Sus antecedentes:
- La depredación de los invertebrados marinos proporciona información sobre los ecosistemas antiguos.
- Los braquiópodos paleozoicos exhiben un registro fósil distinto de depredación en comparación con la fauna marina posterior.
Objetivo del estudio:
- Para analizar la frecuencia y los patrones de los ataques depredadores a los braquiópodos del Paleozoico.
- Comprender las implicaciones ecológicas y evolutivas de la depredación en braquiópodos.
Principales métodos:
- Análisis del registro fósil, específicamente examinando las frecuencias de perforación en las conchas de braquiópodos.
- Análisis estratigráfico y de distribución geográfica de la evidencia de la depredación.
Principales resultados:
- Las frecuencias de perforación en braquiópodos del Paleozoico fueron consistentemente bajas (<1% en el Paleozoico temprano, ligeramente aumentando en el Paleozoico medio a tardío).
- La depredación de braquiópodos estaba geográficamente extendida, pero estratigráficamente rara, especialmente en comparación con los moluscos del pospaleozoico.
- Los braquiópodos actuales muestran solo frecuencias de perforación ligeramente más altas.
Conclusiones:
- La rareza de la perforación sugiere que los braquiópodos eran a menudo objetivos secundarios de los depredadores que atacaban a otros taxones.
- La depredación esporádica aumentó con el aumento de los sistemas tróficos y la diversidad de depredadores.
- Algunas interacciones bióticas persistentes pueden ser accidentales, no necesariamente coevolucionarias.
Videos de Conceptos Relacionados
Inclusive Fitness
Most altruistic behavior—in which one animal helps another at a cost to themselves—occurs between relatives. Scientists think these altruistic behaviors evolved because they increase the inclusive fitness of the animal providing help.
What is Natural Selection?
Natural selection is an evolutionary process in which individuals with survival-promoting traits reproduce at higher rates. These favorable traits become more common within a population or species. Naturally selected traits initially arise via random genetic mutations. In order for selection to occur, there must be variation within a population, the trait controlling the variation must be heritable, and there must be an evolutionary advantage for variation in the trait.The Theory of Natural...
Competition
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.Intraspecific competition, which occurs between individuals of the same species, serves as a natural mechanism for regulating population size. Too much...
Predator-Prey Interactions
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...
Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
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...

