Komerční prezentace
Registrace uživatele

Přihlašte se k odběru informací, novinek, získejte přístup do diskuzního fóra.

Vesmír č. 10
Vesmír č. 10
Toto číslo vychází
2. 10. 2017
Zdarma jedno celé číslo Vesmíru v pdf.
• Říjnové číslo Vesmíru

Těšíte se na nové druhy? Jistě přijdou, ale chce to trpělivost…

Looking forward new species? Patience, please… by Petr Pokorný.

Global environmental changes that swept the Earth over Quaternary period have no analogues in the last 250 millions of years. These have caused enormous and repeated changes in life histories of many species. Theoretical models speak about enhanced evolutionary rate in this period due to allopatric speciation and genetic drift. Nevertheless, comparison of speciation frequencies over entire geological history (based on “molecular clock” and fossil data) shows different pattern. There is no extraordinary evolutionary radiation during Quaternary observable. The solution of this dilemma probably resides in temporal scaling: Quaternary changes last too short to promote observable evolutionary changes in the level of species and above. Timing is everything in this story.