منابع مشابه
Variance Morphology and Evolution
The lifetimes of chromospheric active regions and active region complexes (\active longitudes") for 35 lower main sequence stars observed at Mount Wilson Observatory are estimated from the relative distribution of pooled variance at diierent time scales. The time scale of active region evolution (i.e., the lifetime of large active regions) is approximately 50 days, while the lifetime of active ...
متن کاملEnvironmental Influence on Dental Morphology
Development is a complex phenomenon where the forming phenotype interacts with genetic and environmental inputs. Teeth are an important model for developmental studies and their development has been thoroughly investigated. However, despite of an extensive literature on the genetics of dental development, no studies have yet focused on the environmental influences on dental morphology. Here we ...
متن کاملThe Dental Morphology of Pima
Fourteen morphologic crown traits were observed in a sample of 1528 Pima Indians of south-central Arizona. Pima dentitions are characterized by high frequencies of shoveling, incisor winging, the hypocone, the lower canine distal accessory ridge, cusp 6, and the protostylid. They exhibit low frequencies of the metaconule and lower premolar multiple lingual cusps and moderate frequencies of the ...
متن کاملEvolution of pollen morphology.
Over evolutionary time, the morphology of angiosperm pollen has evolved toward an increasing number of apertures, among other things. From a neo-Darwinian point of view, this means that (i) some polymorphism for aperture number must exist and (ii) there must be some fitness increase associated with increasing the aperture number. Pollen types with different aperture numbers often occur in the s...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Evolution
سال: 1972
ISSN: 0014-3820
DOI: 10.1111/j.1558-5646.1972.tb01977.x