So how did the ancient ancestors of starfish go from having bilateral symmetry to having radial symmetry?

那么海星的远古祖先是如何从左右对称变对称的呢？

The evolutionary past of starfishes from bilateral to radial animals is also echoed in their development.

海星从双侧动物到动物的进化历史也反映在它们的发展过程中。

Sea cucumbers are members of the phylum Echinodermata, along with sea urchins, starfish and other radially symmetrical, " spiny-skinned" marine invertebrates.

海参是棘皮动物门的员，还有海胆、海星和其他对称的“多刺”海洋无脊椎动物。

What might normally be a nonstop trip typically turns either into a one-stop one or one with a bit more walking thanks to this overlapping, less radial design.

由于这种重叠的、较少的设，通常的不间断旅行通常会变一站式旅行或需要更多步行的旅行。

At 4: 29 pm on Tuesday, some six and a half hours after launch, the Shenzhou-16 spacecraft docked with the Tianhe core module's radial port, announced the CMSA.

中国航天局宣布，周二下午4点29分，发射约6个半小时后，神舟16号飞船与天河核心舱的端口对接。

Unlike the Grand Canyon, it wasn't carved by water; it may have formed when the Tharsis bulge rose up, creating the valley as a radial crack in the surface.

与大峡不同，它不是由水流蚀刻而的；水手能是在塔尔西斯隆起升起时，在火星表面形的裂痕。

Radial gates control how much water is released and massive  concrete blocks at the bottom of the chute, called dentates, disperse the flow to reduce erosion as  it crashes into the Feather River.

闸门控制释放的水量，滑槽底部的巨大混凝土块（称为齿状）以分散水流，以减少水流流入羽毛河时的侵蚀。

The facility consists of an earthen embankment which forms  the dam itself, a hydropower generation plant that can be reversed to create pumped storage, a service spillway with 8 radial floodgates, and an emergency overflow spillway.

该设施包括形大坝本身的土堤、反转以形抽水蓄能的水力发电厂、带有 8 个闸门的服务溢洪道以及紧急溢流溢洪道。

This is in contrast to a system like Paris' who's less radial design allows for viable subway routings between most all destinations in the urban core, meaning it is competitive versus cars on trips with more than two nodes.

这与像巴黎这样的系统形鲜明对比，巴黎的系统的设较少，以在城市核心的大多数目的地之间提供行的地铁路线，这意味着它与具有两个以上节点的旅行中的汽车相比具有竞争力。