英文字典中文字典


英文字典中文字典51ZiDian.com



中文字典辞典   英文字典 a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p   q   r   s   t   u   v   w   x   y   z       







请输入英文单字,中文词皆可:

cenogenesis    
n. 新生性变异

新生性变异

cenogenesis
n 1: introduction during embryonic development of characters or
structure not present in the earlier evolutionary history
of the strain or species (such as the addition of the
placenta in mammalian evolution) [synonym: {cenogenesis},
{kenogenesis}, {caenogenesis}, {cainogenesis},
{kainogenesis}] [ant: {palingenesis}, {recapitulation}]

Kenogenesis \Ken`o*gen"e*sis\, n. [Gr. ? new E. genesis.]
(Biol.)
Modified evolution, in which nonprimitive characters make
their appearance in consequence of a secondary adaptation of
the embryo to the peculiar conditions of its environment; --
distinguished from {palingenesis}. [Written also
{cenogenesis} and {c[ae]nogenesis}.]
[1913 Webster]


Recapitulation \Re`ca*pit`u*la"tion\
(r[=e]`k[.a]*p[i^]t"[-u]*l[=a]"sh[u^]n), n. [LL.
recapitulatio: cf. F. recapitulation.]
1. The act of recapitulating; a summary, or concise statement
or enumeration, of the principal points, facts, or
statements, in a preceding discourse, argument, or essay.
[1913 Webster]

2. (Zool.) That process of development of the individual
organism from the embryonic stage onward, which displays a
parallel between the development of an individual animal
(ontogeny) and the historical evolution of the species
(phylogeny). Some authors recognize two types of
recapitulation, {palingenesis}, in which the truly
ancestral characters conserved by heredity are reproduced
during development; and {cenogenesis} ({kenogenesis} or
{coenogenesis}), the mode of individual development in
which alterations in the development process have changed
the original process of recapitulation and obscured the
evolutionary pathway.
[PJC]

This parallel is explained by the theory of
evolution, according to which, in the words of
Sidgwick, "the developmental history of the
individual appears to be a short and simplified
repetition, or in a certain sense a recapitulation,
of the course of development of the species."
Examples of recapitulation may be found in the
embryological development of all vertebrates. Thus
the frog develops through stages in which the embryo
just before hatching is very fish-like, after
hatching becomes a tadpole which exhibits many
newt-like characters; and finally reaches the
permanent frog stage. This accords with the
comparative rank of the fish, newt and frog groups
in classification; and also with the succession
appearance of these groups. Man, as the highest
animal, exhibits most completely these phenomena. In
the earliest stages the human embryo is
indistinguishable from that of any other creature. A
little later the cephalic region shows gill-slits,
like those which in a shark are a permanent feature,
and the heart is two-chambered or fish-like. Further
development closes the gill-slits, and the heart
changes to the reptilian type. Here the reptiles
stop, while birds and mammals advance further; but
the human embryo in its progress to the higher type
recapitulates and leaves features characteristic of
lower mammalian forms -- for instance, a distinct
and comparatively long tail exists. Most of these
changes are completed before the embryo is six weeks
old, but some traces of primitive and obsolete
structures persist throughout life as "vestiges" or
"rudimentary organs," and others appear after birth
in infancy, as the well-known tendency of babies to
turn their feet sideways and inward, and to use
their toes and feet as grasping organs, after the
manner of monkeys. This recapitulation of ancestral
characters in ontogeny is not complete, however, for
not all the stages are reproduced in every case, so
far as can be perceived; and it is irregular and
complicated in various ways among others by the
inheritance of acquired characters. The most special
students of it, as Haeckel, Fritz M["u]tter, Hyatt,
Balfour, etc., distinguish two sorts of
recapitulation {palingenesis}, exemplified in
amphibian larvae and {coenogenesis}, the last
manifested most completely in the metamorphoses of
insects. Palingenesis is recapitulation without any
fundamental changes due to the later modification of
the primitive method of development, while in
coenogenesis, the mode of development has suffered
alterations which obscure the original process of
recapitulation, or support it entirely.
--Encyclopedia
Americana,
1961.
[PJC]


cenogenesis \cen`o*gen"e*sis\ n. [Gr. ? new E. genesis.]
(Biol.)
The introduction during embryonic development of characters
or structure not present in the earlier evolutionary history
of the strain or species (as addition of the placenta in
mammalian evolution); a modified evolution, in which
nonprimitive characters make their appearance in consequence
of a secondary adaptation of the embryo to the peculiar
conditions of its environment; -- distinguished from
{palingenesis}. [Also spelled {caenogenesis} and formerly
{kenogenesis}.]
[WordNet 1.5 1913 Webster]


请选择你想看的字典辞典:
单词字典翻译
cenogenesis查看 cenogenesis 在百度字典中的解释百度英翻中〔查看〕
cenogenesis查看 cenogenesis 在Google字典中的解释Google英翻中〔查看〕
cenogenesis查看 cenogenesis 在Yahoo字典中的解释Yahoo英翻中〔查看〕





安装中文字典英文字典查询工具!


中文字典英文字典工具:
选择颜色:
输入中英文单字

































































英文字典中文字典相关资料:


  • Canadas Work Casual Apparel Store | Marks
    Mark's, Formerly Known As Mark's Work Wearhouse, Is Canada's Top Apparel And Workwear Destination Shop Men’s And Women’s Jeans, Shoes, Shirts, Jackets And More
  • Marks Flyer Weekly Deals
    Operating in Canada since 1977 (as part of the Canadian Tire since 2001), Marks has grown to become one of the country’s most trustworthy apparel and footwear retailers
  • Marks Commercial
    Mark’s Commercial supplies thousands of businesses across Canada with compliant industrial workwear, footwear and PPE as well as branded uniforms and apparel Outfit your crew from head to toe through bulk wholesale programs that send you the right products, to the right place, at the right time
  • Mens Clothing - Marks
    Shop our range of men's clothing in stores across Canada From casual options to workwear essentials, find a variety of apparel that fit your needs
  • Sale | Clearance - Marks
    Discover great deals on men's and women's clothing, footwear, and accessories at Mark's Sale Clearance section
  • Shoes - Marks
    Find a wide range of men's and women's boots and shoes Available in various sizes, choose from casual, formal, or athletic styles for work and weekends
  • Sales - Marks
    Shop the clothing you want from Marks and L’Équipeur at prices you’ll love! No matter what you need for work, you’ll find everything you need from work boots, non-slip shoes and safety shoes, work shirts, work pants, coveralls, work gloves, PPE, and anything the job calls for
  • Womens Clothing - Marks
    Shop our selection of women's tops for work and leisure From blouses to T-shirts, hoodies to sweatshirts and more, find many styles to match your needs
  • ONLINE ORDERING - Marks
    Experience the convenience of real-time order tracking and have your order delivered to you either on the same day or the next day Enjoy the convenience of having thousands of products delivered where you need them How much is it? Pick Up is free Same-Day Delivery - $9 99 flat fee + tax Next-Day Delivery - $7 99 flat fee + tax
  • Welcome to the new way to practice learn - Marks
    Download the app now from Google Play and start your preparation with Chapter wise Questions, Custom Tests, Preparation Tracker, Revision Notes, Formula Sheets much more





中文字典-英文字典  2005-2009